summaryrefslogtreecommitdiff
path: root/revision.c
blob: d4aaf0ef257943029923f741b4ae383bb00d7f5f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
#include "cache.h"
#include "object-store.h"
#include "tag.h"
#include "blob.h"
#include "tree.h"
#include "commit.h"
#include "diff.h"
#include "refs.h"
#include "revision.h"
#include "repository.h"
#include "graph.h"
#include "grep.h"
#include "reflog-walk.h"
#include "patch-ids.h"
#include "decorate.h"
#include "log-tree.h"
#include "string-list.h"
#include "line-log.h"
#include "mailmap.h"
#include "commit-slab.h"
#include "dir.h"
#include "cache-tree.h"
#include "bisect.h"
#include "packfile.h"
#include "worktree.h"
#include "argv-array.h"
#include "commit-reach.h"
#include "commit-graph.h"
#include "prio-queue.h"
#include "hashmap.h"

volatile show_early_output_fn_t show_early_output;

static const char *term_bad;
static const char *term_good;

implement_shared_commit_slab(revision_sources, char *);

void show_object_with_name(FILE *out, struct object *obj, const char *name)
{
	const char *p;

	fprintf(out, "%s ", oid_to_hex(&obj->oid));
	for (p = name; *p && *p != '\n'; p++)
		fputc(*p, out);
	fputc('\n', out);
}

static void mark_blob_uninteresting(struct blob *blob)
{
	if (!blob)
		return;
	if (blob->object.flags & UNINTERESTING)
		return;
	blob->object.flags |= UNINTERESTING;
}

static void mark_tree_contents_uninteresting(struct repository *r,
					     struct tree *tree)
{
	struct tree_desc desc;
	struct name_entry entry;

	if (parse_tree_gently(tree, 1) < 0)
		return;

	init_tree_desc(&desc, tree->buffer, tree->size);
	while (tree_entry(&desc, &entry)) {
		switch (object_type(entry.mode)) {
		case OBJ_TREE:
			mark_tree_uninteresting(r, lookup_tree(r, &entry.oid));
			break;
		case OBJ_BLOB:
			mark_blob_uninteresting(lookup_blob(r, &entry.oid));
			break;
		default:
			/* Subproject commit - not in this repository */
			break;
		}
	}

	/*
	 * We don't care about the tree any more
	 * after it has been marked uninteresting.
	 */
	free_tree_buffer(tree);
}

void mark_tree_uninteresting(struct repository *r, struct tree *tree)
{
	struct object *obj;

	if (!tree)
		return;

	obj = &tree->object;
	if (obj->flags & UNINTERESTING)
		return;
	obj->flags |= UNINTERESTING;
	mark_tree_contents_uninteresting(r, tree);
}

struct path_and_oids_entry {
	struct hashmap_entry ent;
	char *path;
	struct oidset trees;
};

static int path_and_oids_cmp(const void *hashmap_cmp_fn_data,
			     const struct path_and_oids_entry *e1,
			     const struct path_and_oids_entry *e2,
			     const void *keydata)
{
	return strcmp(e1->path, e2->path);
}

static void paths_and_oids_init(struct hashmap *map)
{
	hashmap_init(map, (hashmap_cmp_fn) path_and_oids_cmp, NULL, 0);
}

static void paths_and_oids_clear(struct hashmap *map)
{
	struct hashmap_iter iter;
	struct path_and_oids_entry *entry;
	hashmap_iter_init(map, &iter);

	while ((entry = (struct path_and_oids_entry *)hashmap_iter_next(&iter))) {
		oidset_clear(&entry->trees);
		free(entry->path);
	}

	hashmap_free(map, 1);
}

static void paths_and_oids_insert(struct hashmap *map,
				  const char *path,
				  const struct object_id *oid)
{
	int hash = strhash(path);
	struct path_and_oids_entry key;
	struct path_and_oids_entry *entry;

	hashmap_entry_init(&key, hash);

	/* use a shallow copy for the lookup */
	key.path = (char *)path;
	oidset_init(&key.trees, 0);

	if (!(entry = (struct path_and_oids_entry *)hashmap_get(map, &key, NULL))) {
		entry = xcalloc(1, sizeof(struct path_and_oids_entry));
		hashmap_entry_init(entry, hash);
		entry->path = xstrdup(key.path);
		oidset_init(&entry->trees, 16);
		hashmap_put(map, entry);
	}

	oidset_insert(&entry->trees, oid);
}

static void add_children_by_path(struct repository *r,
				 struct tree *tree,
				 struct hashmap *map)
{
	struct tree_desc desc;
	struct name_entry entry;

	if (!tree)
		return;

	if (parse_tree_gently(tree, 1) < 0)
		return;

	init_tree_desc(&desc, tree->buffer, tree->size);
	while (tree_entry(&desc, &entry)) {
		switch (object_type(entry.mode)) {
		case OBJ_TREE:
			paths_and_oids_insert(map, entry.path, &entry.oid);

			if (tree->object.flags & UNINTERESTING) {
				struct tree *child = lookup_tree(r, &entry.oid);
				if (child)
					child->object.flags |= UNINTERESTING;
			}
			break;
		case OBJ_BLOB:
			if (tree->object.flags & UNINTERESTING) {
				struct blob *child = lookup_blob(r, &entry.oid);
				if (child)
					child->object.flags |= UNINTERESTING;
			}
			break;
		default:
			/* Subproject commit - not in this repository */
			break;
		}
	}

	free_tree_buffer(tree);
}

void mark_trees_uninteresting_sparse(struct repository *r,
				     struct oidset *trees)
{
	unsigned has_interesting = 0, has_uninteresting = 0;
	struct hashmap map;
	struct hashmap_iter map_iter;
	struct path_and_oids_entry *entry;
	struct object_id *oid;
	struct oidset_iter iter;

	oidset_iter_init(trees, &iter);
	while ((!has_interesting || !has_uninteresting) &&
	       (oid = oidset_iter_next(&iter))) {
		struct tree *tree = lookup_tree(r, oid);

		if (!tree)
			continue;

		if (tree->object.flags & UNINTERESTING)
			has_uninteresting = 1;
		else
			has_interesting = 1;
	}

	/* Do not walk unless we have both types of trees. */
	if (!has_uninteresting || !has_interesting)
		return;

	paths_and_oids_init(&map);

	oidset_iter_init(trees, &iter);
	while ((oid = oidset_iter_next(&iter))) {
		struct tree *tree = lookup_tree(r, oid);
		add_children_by_path(r, tree, &map);
	}

	hashmap_iter_init(&map, &map_iter);
	while ((entry = hashmap_iter_next(&map_iter)))
		mark_trees_uninteresting_sparse(r, &entry->trees);

	paths_and_oids_clear(&map);
}

struct commit_stack {
	struct commit **items;
	size_t nr, alloc;
};
#define COMMIT_STACK_INIT { NULL, 0, 0 }

static void commit_stack_push(struct commit_stack *stack, struct commit *commit)
{
	ALLOC_GROW(stack->items, stack->nr + 1, stack->alloc);
	stack->items[stack->nr++] = commit;
}

static struct commit *commit_stack_pop(struct commit_stack *stack)
{
	return stack->nr ? stack->items[--stack->nr] : NULL;
}

static void commit_stack_clear(struct commit_stack *stack)
{
	FREE_AND_NULL(stack->items);
	stack->nr = stack->alloc = 0;
}

static void mark_one_parent_uninteresting(struct commit *commit,
					  struct commit_stack *pending)
{
	struct commit_list *l;

	if (commit->object.flags & UNINTERESTING)
		return;
	commit->object.flags |= UNINTERESTING;

	/*
	 * Normally we haven't parsed the parent
	 * yet, so we won't have a parent of a parent
	 * here. However, it may turn out that we've
	 * reached this commit some other way (where it
	 * wasn't uninteresting), in which case we need
	 * to mark its parents recursively too..
	 */
	for (l = commit->parents; l; l = l->next)
		commit_stack_push(pending, l->item);
}

void mark_parents_uninteresting(struct commit *commit)
{
	struct commit_stack pending = COMMIT_STACK_INIT;
	struct commit_list *l;

	for (l = commit->parents; l; l = l->next)
		mark_one_parent_uninteresting(l->item, &pending);

	while (pending.nr > 0)
		mark_one_parent_uninteresting(commit_stack_pop(&pending),
					      &pending);

	commit_stack_clear(&pending);
}

static void add_pending_object_with_path(struct rev_info *revs,
					 struct object *obj,
					 const char *name, unsigned mode,
					 const char *path)
{
	if (!obj)
		return;
	if (revs->no_walk && (obj->flags & UNINTERESTING))
		revs->no_walk = 0;
	if (revs->reflog_info && obj->type == OBJ_COMMIT) {
		struct strbuf buf = STRBUF_INIT;
		int len = interpret_branch_name(name, 0, &buf, 0);

		if (0 < len && name[len] && buf.len)
			strbuf_addstr(&buf, name + len);
		add_reflog_for_walk(revs->reflog_info,
				    (struct commit *)obj,
				    buf.buf[0] ? buf.buf: name);
		strbuf_release(&buf);
		return; /* do not add the commit itself */
	}
	add_object_array_with_path(obj, name, &revs->pending, mode, path);
}

static void add_pending_object_with_mode(struct rev_info *revs,
					 struct object *obj,
					 const char *name, unsigned mode)
{
	add_pending_object_with_path(revs, obj, name, mode, NULL);
}

void add_pending_object(struct rev_info *revs,
			struct object *obj, const char *name)
{
	add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
}

void add_head_to_pending(struct rev_info *revs)
{
	struct object_id oid;
	struct object *obj;
	if (get_oid("HEAD", &oid))
		return;
	obj = parse_object(revs->repo, &oid);
	if (!obj)
		return;
	add_pending_object(revs, obj, "HEAD");
}

static struct object *get_reference(struct rev_info *revs, const char *name,
				    const struct object_id *oid,
				    unsigned int flags)
{
	struct object *object;

	/*
	 * If the repository has commit graphs, repo_parse_commit() avoids
	 * reading the object buffer, so use it whenever possible.
	 */
	if (oid_object_info(revs->repo, oid, NULL) == OBJ_COMMIT) {
		struct commit *c = lookup_commit(revs->repo, oid);
		if (!repo_parse_commit(revs->repo, c))
			object = (struct object *) c;
		else
			object = NULL;
	} else {
		object = parse_object(revs->repo, oid);
	}

	if (!object) {
		if (revs->ignore_missing)
			return object;
		if (revs->exclude_promisor_objects && is_promisor_object(oid))
			return NULL;
		die("bad object %s", name);
	}
	object->flags |= flags;
	return object;
}

void add_pending_oid(struct rev_info *revs, const char *name,
		      const struct object_id *oid, unsigned int flags)
{
	struct object *object = get_reference(revs, name, oid, flags);
	add_pending_object(revs, object, name);
}

static struct commit *handle_commit(struct rev_info *revs,
				    struct object_array_entry *entry)
{
	struct object *object = entry->item;
	const char *name = entry->name;
	const char *path = entry->path;
	unsigned int mode = entry->mode;
	unsigned long flags = object->flags;

	/*
	 * Tag object? Look what it points to..
	 */
	while (object->type == OBJ_TAG) {
		struct tag *tag = (struct tag *) object;
		if (revs->tag_objects && !(flags & UNINTERESTING))
			add_pending_object(revs, object, tag->tag);
		if (!tag->tagged)
			die("bad tag");
		object = parse_object(revs->repo, &tag->tagged->oid);
		if (!object) {
			if (revs->ignore_missing_links || (flags & UNINTERESTING))
				return NULL;
			if (revs->exclude_promisor_objects &&
			    is_promisor_object(&tag->tagged->oid))
				return NULL;
			die("bad object %s", oid_to_hex(&tag->tagged->oid));
		}
		object->flags |= flags;
		/*
		 * We'll handle the tagged object by looping or dropping
		 * through to the non-tag handlers below. Do not
		 * propagate path data from the tag's pending entry.
		 */
		path = NULL;
		mode = 0;
	}

	/*
	 * Commit object? Just return it, we'll do all the complex
	 * reachability crud.
	 */
	if (object->type == OBJ_COMMIT) {
		struct commit *commit = (struct commit *)object;

		if (parse_commit(commit) < 0)
			die("unable to parse commit %s", name);
		if (flags & UNINTERESTING) {
			mark_parents_uninteresting(commit);
			revs->limited = 1;
		}
		if (revs->sources) {
			char **slot = revision_sources_at(revs->sources, commit);

			if (!*slot)
				*slot = xstrdup(name);
		}
		return commit;
	}

	/*
	 * Tree object? Either mark it uninteresting, or add it
	 * to the list of objects to look at later..
	 */
	if (object->type == OBJ_TREE) {
		struct tree *tree = (struct tree *)object;
		if (!revs->tree_objects)
			return NULL;
		if (flags & UNINTERESTING) {
			mark_tree_contents_uninteresting(revs->repo, tree);
			return NULL;
		}
		add_pending_object_with_path(revs, object, name, mode, path);
		return NULL;
	}

	/*
	 * Blob object? You know the drill by now..
	 */
	if (object->type == OBJ_BLOB) {
		if (!revs->blob_objects)
			return NULL;
		if (flags & UNINTERESTING)
			return NULL;
		add_pending_object_with_path(revs, object, name, mode, path);
		return NULL;
	}
	die("%s is unknown object", name);
}

static int everybody_uninteresting(struct commit_list *orig,
				   struct commit **interesting_cache)
{
	struct commit_list *list = orig;

	if (*interesting_cache) {
		struct commit *commit = *interesting_cache;
		if (!(commit->object.flags & UNINTERESTING))
			return 0;
	}

	while (list) {
		struct commit *commit = list->item;
		list = list->next;
		if (commit->object.flags & UNINTERESTING)
			continue;

		*interesting_cache = commit;
		return 0;
	}
	return 1;
}

/*
 * A definition of "relevant" commit that we can use to simplify limited graphs
 * by eliminating side branches.
 *
 * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
 * in our list), or that is a specified BOTTOM commit. Then after computing
 * a limited list, during processing we can generally ignore boundary merges
 * coming from outside the graph, (ie from irrelevant parents), and treat
 * those merges as if they were single-parent. TREESAME is defined to consider
 * only relevant parents, if any. If we are TREESAME to our on-graph parents,
 * we don't care if we were !TREESAME to non-graph parents.
 *
 * Treating bottom commits as relevant ensures that a limited graph's
 * connection to the actual bottom commit is not viewed as a side branch, but
 * treated as part of the graph. For example:
 *
 *   ....Z...A---X---o---o---B
 *        .     /
 *         W---Y
 *
 * When computing "A..B", the A-X connection is at least as important as
 * Y-X, despite A being flagged UNINTERESTING.
 *
 * And when computing --ancestry-path "A..B", the A-X connection is more
 * important than Y-X, despite both A and Y being flagged UNINTERESTING.
 */
static inline int relevant_commit(struct commit *commit)
{
	return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
}

/*
 * Return a single relevant commit from a parent list. If we are a TREESAME
 * commit, and this selects one of our parents, then we can safely simplify to
 * that parent.
 */
static struct commit *one_relevant_parent(const struct rev_info *revs,
					  struct commit_list *orig)
{
	struct commit_list *list = orig;
	struct commit *relevant = NULL;

	if (!orig)
		return NULL;

	/*
	 * For 1-parent commits, or if first-parent-only, then return that
	 * first parent (even if not "relevant" by the above definition).
	 * TREESAME will have been set purely on that parent.
	 */
	if (revs->first_parent_only || !orig->next)
		return orig->item;

	/*
	 * For multi-parent commits, identify a sole relevant parent, if any.
	 * If we have only one relevant parent, then TREESAME will be set purely
	 * with regard to that parent, and we can simplify accordingly.
	 *
	 * If we have more than one relevant parent, or no relevant parents
	 * (and multiple irrelevant ones), then we can't select a parent here
	 * and return NULL.
	 */
	while (list) {
		struct commit *commit = list->item;
		list = list->next;
		if (relevant_commit(commit)) {
			if (relevant)
				return NULL;
			relevant = commit;
		}
	}
	return relevant;
}

/*
 * The goal is to get REV_TREE_NEW as the result only if the
 * diff consists of all '+' (and no other changes), REV_TREE_OLD
 * if the whole diff is removal of old data, and otherwise
 * REV_TREE_DIFFERENT (of course if the trees are the same we
 * want REV_TREE_SAME).
 *
 * The only time we care about the distinction is when
 * remove_empty_trees is in effect, in which case we care only about
 * whether the whole change is REV_TREE_NEW, or if there's another type
 * of change. Which means we can stop the diff early in either of these
 * cases:
 *
 *   1. We're not using remove_empty_trees at all.
 *
 *   2. We saw anything except REV_TREE_NEW.
 */
static int tree_difference = REV_TREE_SAME;

static void file_add_remove(struct diff_options *options,
		    int addremove, unsigned mode,
		    const struct object_id *oid,
		    int oid_valid,
		    const char *fullpath, unsigned dirty_submodule)
{
	int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
	struct rev_info *revs = options->change_fn_data;

	tree_difference |= diff;
	if (!revs->remove_empty_trees || tree_difference != REV_TREE_NEW)
		options->flags.has_changes = 1;
}

static void file_change(struct diff_options *options,
		 unsigned old_mode, unsigned new_mode,
		 const struct object_id *old_oid,
		 const struct object_id *new_oid,
		 int old_oid_valid, int new_oid_valid,
		 const char *fullpath,
		 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
{
	tree_difference = REV_TREE_DIFFERENT;
	options->flags.has_changes = 1;
}

static int rev_compare_tree(struct rev_info *revs,
			    struct commit *parent, struct commit *commit)
{
	struct tree *t1 = get_commit_tree(parent);
	struct tree *t2 = get_commit_tree(commit);

	if (!t1)
		return REV_TREE_NEW;
	if (!t2)
		return REV_TREE_OLD;

	if (revs->simplify_by_decoration) {
		/*
		 * If we are simplifying by decoration, then the commit
		 * is worth showing if it has a tag pointing at it.
		 */
		if (get_name_decoration(&commit->object))
			return REV_TREE_DIFFERENT;
		/*
		 * A commit that is not pointed by a tag is uninteresting
		 * if we are not limited by path.  This means that you will
		 * see the usual "commits that touch the paths" plus any
		 * tagged commit by specifying both --simplify-by-decoration
		 * and pathspec.
		 */
		if (!revs->prune_data.nr)
			return REV_TREE_SAME;
	}

	tree_difference = REV_TREE_SAME;
	revs->pruning.flags.has_changes = 0;
	if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
			   &revs->pruning) < 0)
		return REV_TREE_DIFFERENT;
	return tree_difference;
}

static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
{
	int retval;
	struct tree *t1 = get_commit_tree(commit);

	if (!t1)
		return 0;

	tree_difference = REV_TREE_SAME;
	revs->pruning.flags.has_changes = 0;
	retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);

	return retval >= 0 && (tree_difference == REV_TREE_SAME);
}

struct treesame_state {
	unsigned int nparents;
	unsigned char treesame[FLEX_ARRAY];
};

static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
{
	unsigned n = commit_list_count(commit->parents);
	struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n));
	st->nparents = n;
	add_decoration(&revs->treesame, &commit->object, st);
	return st;
}

/*
 * Must be called immediately after removing the nth_parent from a commit's
 * parent list, if we are maintaining the per-parent treesame[] decoration.
 * This does not recalculate the master TREESAME flag - update_treesame()
 * should be called to update it after a sequence of treesame[] modifications
 * that may have affected it.
 */
static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
{
	struct treesame_state *st;
	int old_same;

	if (!commit->parents) {
		/*
		 * Have just removed the only parent from a non-merge.
		 * Different handling, as we lack decoration.
		 */
		if (nth_parent != 0)
			die("compact_treesame %u", nth_parent);
		old_same = !!(commit->object.flags & TREESAME);
		if (rev_same_tree_as_empty(revs, commit))
			commit->object.flags |= TREESAME;
		else
			commit->object.flags &= ~TREESAME;
		return old_same;
	}

	st = lookup_decoration(&revs->treesame, &commit->object);
	if (!st || nth_parent >= st->nparents)
		die("compact_treesame %u", nth_parent);

	old_same = st->treesame[nth_parent];
	memmove(st->treesame + nth_parent,
		st->treesame + nth_parent + 1,
		st->nparents - nth_parent - 1);

	/*
	 * If we've just become a non-merge commit, update TREESAME
	 * immediately, and remove the no-longer-needed decoration.
	 * If still a merge, defer update until update_treesame().
	 */
	if (--st->nparents == 1) {
		if (commit->parents->next)
			die("compact_treesame parents mismatch");
		if (st->treesame[0] && revs->dense)
			commit->object.flags |= TREESAME;
		else
			commit->object.flags &= ~TREESAME;
		free(add_decoration(&revs->treesame, &commit->object, NULL));
	}

	return old_same;
}

static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
{
	if (commit->parents && commit->parents->next) {
		unsigned n;
		struct treesame_state *st;
		struct commit_list *p;
		unsigned relevant_parents;
		unsigned relevant_change, irrelevant_change;

		st = lookup_decoration(&revs->treesame, &commit->object);
		if (!st)
			die("update_treesame %s", oid_to_hex(&commit->object.oid));
		relevant_parents = 0;
		relevant_change = irrelevant_change = 0;
		for (p = commit->parents, n = 0; p; n++, p = p->next) {
			if (relevant_commit(p->item)) {
				relevant_change |= !st->treesame[n];
				relevant_parents++;
			} else
				irrelevant_change |= !st->treesame[n];
		}
		if (relevant_parents ? relevant_change : irrelevant_change)
			commit->object.flags &= ~TREESAME;
		else
			commit->object.flags |= TREESAME;
	}

	return commit->object.flags & TREESAME;
}

static inline int limiting_can_increase_treesame(const struct rev_info *revs)
{
	/*
	 * TREESAME is irrelevant unless prune && dense;
	 * if simplify_history is set, we can't have a mixture of TREESAME and
	 *    !TREESAME INTERESTING parents (and we don't have treesame[]
	 *    decoration anyway);
	 * if first_parent_only is set, then the TREESAME flag is locked
	 *    against the first parent (and again we lack treesame[] decoration).
	 */
	return revs->prune && revs->dense &&
	       !revs->simplify_history &&
	       !revs->first_parent_only;
}

static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
{
	struct commit_list **pp, *parent;
	struct treesame_state *ts = NULL;
	int relevant_change = 0, irrelevant_change = 0;
	int relevant_parents, nth_parent;

	/*
	 * If we don't do pruning, everything is interesting
	 */
	if (!revs->prune)
		return;

	if (!get_commit_tree(commit))
		return;

	if (!commit->parents) {
		if (rev_same_tree_as_empty(revs, commit))
			commit->object.flags |= TREESAME;
		return;
	}

	/*
	 * Normal non-merge commit? If we don't want to make the
	 * history dense, we consider it always to be a change..
	 */
	if (!revs->dense && !commit->parents->next)
		return;

	for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
	     (parent = *pp) != NULL;
	     pp = &parent->next, nth_parent++) {
		struct commit *p = parent->item;
		if (relevant_commit(p))
			relevant_parents++;

		if (nth_parent == 1) {
			/*
			 * This our second loop iteration - so we now know
			 * we're dealing with a merge.
			 *
			 * Do not compare with later parents when we care only about
			 * the first parent chain, in order to avoid derailing the
			 * traversal to follow a side branch that brought everything
			 * in the path we are limited to by the pathspec.
			 */
			if (revs->first_parent_only)
				break;
			/*
			 * If this will remain a potentially-simplifiable
			 * merge, remember per-parent treesame if needed.
			 * Initialise the array with the comparison from our
			 * first iteration.
			 */
			if (revs->treesame.name &&
			    !revs->simplify_history &&
			    !(commit->object.flags & UNINTERESTING)) {
				ts = initialise_treesame(revs, commit);
				if (!(irrelevant_change || relevant_change))
					ts->treesame[0] = 1;
			}
		}
		if (parse_commit(p) < 0)
			die("cannot simplify commit %s (because of %s)",
			    oid_to_hex(&commit->object.oid),
			    oid_to_hex(&p->object.oid));
		switch (rev_compare_tree(revs, p, commit)) {
		case REV_TREE_SAME:
			if (!revs->simplify_history || !relevant_commit(p)) {
				/* Even if a merge with an uninteresting
				 * side branch brought the entire change
				 * we are interested in, we do not want
				 * to lose the other branches of this
				 * merge, so we just keep going.
				 */
				if (ts)
					ts->treesame[nth_parent] = 1;
				continue;
			}
			parent->next = NULL;
			commit->parents = parent;
			commit->object.flags |= TREESAME;
			return;

		case REV_TREE_NEW:
			if (revs->remove_empty_trees &&
			    rev_same_tree_as_empty(revs, p)) {
				/* We are adding all the specified
				 * paths from this parent, so the
				 * history beyond this parent is not
				 * interesting.  Remove its parents
				 * (they are grandparents for us).
				 * IOW, we pretend this parent is a
				 * "root" commit.
				 */
				if (parse_commit(p) < 0)
					die("cannot simplify commit %s (invalid %s)",
					    oid_to_hex(&commit->object.oid),
					    oid_to_hex(&p->object.oid));
				p->parents = NULL;
			}
		/* fallthrough */
		case REV_TREE_OLD:
		case REV_TREE_DIFFERENT:
			if (relevant_commit(p))
				relevant_change = 1;
			else
				irrelevant_change = 1;
			continue;
		}
		die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
	}

	/*
	 * TREESAME is straightforward for single-parent commits. For merge
	 * commits, it is most useful to define it so that "irrelevant"
	 * parents cannot make us !TREESAME - if we have any relevant
	 * parents, then we only consider TREESAMEness with respect to them,
	 * allowing irrelevant merges from uninteresting branches to be
	 * simplified away. Only if we have only irrelevant parents do we
	 * base TREESAME on them. Note that this logic is replicated in
	 * update_treesame, which should be kept in sync.
	 */
	if (relevant_parents ? !relevant_change : !irrelevant_change)
		commit->object.flags |= TREESAME;
}

static int process_parents(struct rev_info *revs, struct commit *commit,
			   struct commit_list **list, struct prio_queue *queue)
{
	struct commit_list *parent = commit->parents;
	unsigned left_flag;

	if (commit->object.flags & ADDED)
		return 0;
	commit->object.flags |= ADDED;

	if (revs->include_check &&
	    !revs->include_check(commit, revs->include_check_data))
		return 0;

	/*
	 * If the commit is uninteresting, don't try to
	 * prune parents - we want the maximal uninteresting
	 * set.
	 *
	 * Normally we haven't parsed the parent
	 * yet, so we won't have a parent of a parent
	 * here. However, it may turn out that we've
	 * reached this commit some other way (where it
	 * wasn't uninteresting), in which case we need
	 * to mark its parents recursively too..
	 */
	if (commit->object.flags & UNINTERESTING) {
		while (parent) {
			struct commit *p = parent->item;
			parent = parent->next;
			if (p)
				p->object.flags |= UNINTERESTING;
			if (parse_commit_gently(p, 1) < 0)
				continue;
			if (p->parents)
				mark_parents_uninteresting(p);
			if (p->object.flags & SEEN)
				continue;
			p->object.flags |= SEEN;
			if (list)
				commit_list_insert_by_date(p, list);
			if (queue)
				prio_queue_put(queue, p);
		}
		return 0;
	}

	/*
	 * Ok, the commit wasn't uninteresting. Try to
	 * simplify the commit history and find the parent
	 * that has no differences in the path set if one exists.
	 */
	try_to_simplify_commit(revs, commit);

	if (revs->no_walk)
		return 0;

	left_flag = (commit->object.flags & SYMMETRIC_LEFT);

	for (parent = commit->parents; parent; parent = parent->next) {
		struct commit *p = parent->item;
		int gently = revs->ignore_missing_links ||
			     revs->exclude_promisor_objects;
		if (parse_commit_gently(p, gently) < 0) {
			if (revs->exclude_promisor_objects &&
			    is_promisor_object(&p->object.oid)) {
				if (revs->first_parent_only)
					break;
				continue;
			}
			return -1;
		}
		if (revs->sources) {
			char **slot = revision_sources_at(revs->sources, p);

			if (!*slot)
				*slot = *revision_sources_at(revs->sources, commit);
		}
		p->object.flags |= left_flag;
		if (!(p->object.flags & SEEN)) {
			p->object.flags |= SEEN;
			if (list)
				commit_list_insert_by_date(p, list);
			if (queue)
				prio_queue_put(queue, p);
		}
		if (revs->first_parent_only)
			break;
	}
	return 0;
}

static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
{
	struct commit_list *p;
	int left_count = 0, right_count = 0;
	int left_first;
	struct patch_ids ids;
	unsigned cherry_flag;

	/* First count the commits on the left and on the right */
	for (p = list; p; p = p->next) {
		struct commit *commit = p->item;
		unsigned flags = commit->object.flags;
		if (flags & BOUNDARY)
			;
		else if (flags & SYMMETRIC_LEFT)
			left_count++;
		else
			right_count++;
	}

	if (!left_count || !right_count)
		return;

	left_first = left_count < right_count;
	init_patch_ids(revs->repo, &ids);
	ids.diffopts.pathspec = revs->diffopt.pathspec;

	/* Compute patch-ids for one side */
	for (p = list; p; p = p->next) {
		struct commit *commit = p->item;
		unsigned flags = commit->object.flags;

		if (flags & BOUNDARY)
			continue;
		/*
		 * If we have fewer left, left_first is set and we omit
		 * commits on the right branch in this loop.  If we have
		 * fewer right, we skip the left ones.
		 */
		if (left_first != !!(flags & SYMMETRIC_LEFT))
			continue;
		add_commit_patch_id(commit, &ids);
	}

	/* either cherry_mark or cherry_pick are true */
	cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;

	/* Check the other side */
	for (p = list; p; p = p->next) {
		struct commit *commit = p->item;
		struct patch_id *id;
		unsigned flags = commit->object.flags;

		if (flags & BOUNDARY)
			continue;
		/*
		 * If we have fewer left, left_first is set and we omit
		 * commits on the left branch in this loop.
		 */
		if (left_first == !!(flags & SYMMETRIC_LEFT))
			continue;

		/*
		 * Have we seen the same patch id?
		 */
		id = has_commit_patch_id(commit, &ids);
		if (!id)
			continue;

		commit->object.flags |= cherry_flag;
		id->commit->object.flags |= cherry_flag;
	}

	free_patch_ids(&ids);
}

/* How many extra uninteresting commits we want to see.. */
#define SLOP 5

static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
			     struct commit **interesting_cache)
{
	/*
	 * No source list at all? We're definitely done..
	 */
	if (!src)
		return 0;

	/*
	 * Does the destination list contain entries with a date
	 * before the source list? Definitely _not_ done.
	 */
	if (date <= src->item->date)
		return SLOP;

	/*
	 * Does the source list still have interesting commits in
	 * it? Definitely not done..
	 */
	if (!everybody_uninteresting(src, interesting_cache))
		return SLOP;

	/* Ok, we're closing in.. */
	return slop-1;
}

/*
 * "rev-list --ancestry-path A..B" computes commits that are ancestors
 * of B but not ancestors of A but further limits the result to those
 * that are descendants of A.  This takes the list of bottom commits and
 * the result of "A..B" without --ancestry-path, and limits the latter
 * further to the ones that can reach one of the commits in "bottom".
 */
static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
{
	struct commit_list *p;
	struct commit_list *rlist = NULL;
	int made_progress;

	/*
	 * Reverse the list so that it will be likely that we would
	 * process parents before children.
	 */
	for (p = list; p; p = p->next)
		commit_list_insert(p->item, &rlist);

	for (p = bottom; p; p = p->next)
		p->item->object.flags |= TMP_MARK;

	/*
	 * Mark the ones that can reach bottom commits in "list",
	 * in a bottom-up fashion.
	 */
	do {
		made_progress = 0;
		for (p = rlist; p; p = p->next) {
			struct commit *c = p->item;
			struct commit_list *parents;
			if (c->object.flags & (TMP_MARK | UNINTERESTING))
				continue;
			for (parents = c->parents;
			     parents;
			     parents = parents->next) {
				if (!(parents->item->object.flags & TMP_MARK))
					continue;
				c->object.flags |= TMP_MARK;
				made_progress = 1;
				break;
			}
		}
	} while (made_progress);

	/*
	 * NEEDSWORK: decide if we want to remove parents that are
	 * not marked with TMP_MARK from commit->parents for commits
	 * in the resulting list.  We may not want to do that, though.
	 */

	/*
	 * The ones that are not marked with TMP_MARK are uninteresting
	 */
	for (p = list; p; p = p->next) {
		struct commit *c = p->item;
		if (c->object.flags & TMP_MARK)
			continue;
		c->object.flags |= UNINTERESTING;
	}

	/* We are done with the TMP_MARK */
	for (p = list; p; p = p->next)
		p->item->object.flags &= ~TMP_MARK;
	for (p = bottom; p; p = p->next)
		p->item->object.flags &= ~TMP_MARK;
	free_commit_list(rlist);
}

/*
 * Before walking the history, keep the set of "negative" refs the
 * caller has asked to exclude.
 *
 * This is used to compute "rev-list --ancestry-path A..B", as we need
 * to filter the result of "A..B" further to the ones that can actually
 * reach A.
 */
static struct commit_list *collect_bottom_commits(struct commit_list *list)
{
	struct commit_list *elem, *bottom = NULL;
	for (elem = list; elem; elem = elem->next)
		if (elem->item->object.flags & BOTTOM)
			commit_list_insert(elem->item, &bottom);
	return bottom;
}

/* Assumes either left_only or right_only is set */
static void limit_left_right(struct commit_list *list, struct rev_info *revs)
{
	struct commit_list *p;

	for (p = list; p; p = p->next) {
		struct commit *commit = p->item;

		if (revs->right_only) {
			if (commit->object.flags & SYMMETRIC_LEFT)
				commit->object.flags |= SHOWN;
		} else	/* revs->left_only is set */
			if (!(commit->object.flags & SYMMETRIC_LEFT))
				commit->object.flags |= SHOWN;
	}
}

static int limit_list(struct rev_info *revs)
{
	int slop = SLOP;
	timestamp_t date = TIME_MAX;
	struct commit_list *list = revs->commits;
	struct commit_list *newlist = NULL;
	struct commit_list **p = &newlist;
	struct commit_list *bottom = NULL;
	struct commit *interesting_cache = NULL;

	if (revs->ancestry_path) {
		bottom = collect_bottom_commits(list);
		if (!bottom)
			die("--ancestry-path given but there are no bottom commits");
	}

	while (list) {
		struct commit *commit = pop_commit(&list);
		struct object *obj = &commit->object;
		show_early_output_fn_t show;

		if (commit == interesting_cache)
			interesting_cache = NULL;

		if (revs->max_age != -1 && (commit->date < revs->max_age))
			obj->flags |= UNINTERESTING;
		if (process_parents(revs, commit, &list, NULL) < 0)
			return -1;
		if (obj->flags & UNINTERESTING) {
			mark_parents_uninteresting(commit);
			slop = still_interesting(list, date, slop, &interesting_cache);
			if (slop)
				continue;
			break;
		}
		if (revs->min_age != -1 && (commit->date > revs->min_age))
			continue;
		date = commit->date;
		p = &commit_list_insert(commit, p)->next;

		show = show_early_output;
		if (!show)
			continue;

		show(revs, newlist);
		show_early_output = NULL;
	}
	if (revs->cherry_pick || revs->cherry_mark)
		cherry_pick_list(newlist, revs);

	if (revs->left_only || revs->right_only)
		limit_left_right(newlist, revs);

	if (bottom) {
		limit_to_ancestry(bottom, newlist);
		free_commit_list(bottom);
	}

	/*
	 * Check if any commits have become TREESAME by some of their parents
	 * becoming UNINTERESTING.
	 */
	if (limiting_can_increase_treesame(revs))
		for (list = newlist; list; list = list->next) {
			struct commit *c = list->item;
			if (c->object.flags & (UNINTERESTING | TREESAME))
				continue;
			update_treesame(revs, c);
		}

	revs->commits = newlist;
	return 0;
}

/*
 * Add an entry to refs->cmdline with the specified information.
 * *name is copied.
 */
static void add_rev_cmdline(struct rev_info *revs,
			    struct object *item,
			    const char *name,
			    int whence,
			    unsigned flags)
{
	struct rev_cmdline_info *info = &revs->cmdline;
	unsigned int nr = info->nr;

	ALLOC_GROW(info->rev, nr + 1, info->alloc);
	info->rev[nr].item = item;
	info->rev[nr].name = xstrdup(name);
	info->rev[nr].whence = whence;
	info->rev[nr].flags = flags;
	info->nr++;
}

static void add_rev_cmdline_list(struct rev_info *revs,
				 struct commit_list *commit_list,
				 int whence,
				 unsigned flags)
{
	while (commit_list) {
		struct object *object = &commit_list->item->object;
		add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
				whence, flags);
		commit_list = commit_list->next;
	}
}

struct all_refs_cb {
	int all_flags;
	int warned_bad_reflog;
	struct rev_info *all_revs;
	const char *name_for_errormsg;
	struct worktree *wt;
};

int ref_excluded(struct string_list *ref_excludes, const char *path)
{
	struct string_list_item *item;

	if (!ref_excludes)
		return 0;
	for_each_string_list_item(item, ref_excludes) {
		if (!wildmatch(item->string, path, 0))
			return 1;
	}
	return 0;
}

static int handle_one_ref(const char *path, const struct object_id *oid,
			  int flag, void *cb_data)
{
	struct all_refs_cb *cb = cb_data;
	struct object *object;

	if (ref_excluded(cb->all_revs->ref_excludes, path))
	    return 0;

	object = get_reference(cb->all_revs, path, oid, cb->all_flags);
	add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
	add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
	return 0;
}

static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
	unsigned flags)
{
	cb->all_revs = revs;
	cb->all_flags = flags;
	revs->rev_input_given = 1;
	cb->wt = NULL;
}

void clear_ref_exclusion(struct string_list **ref_excludes_p)
{
	if (*ref_excludes_p) {
		string_list_clear(*ref_excludes_p, 0);
		free(*ref_excludes_p);
	}
	*ref_excludes_p = NULL;
}

void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
{
	if (!*ref_excludes_p) {
		*ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
		(*ref_excludes_p)->strdup_strings = 1;
	}
	string_list_append(*ref_excludes_p, exclude);
}

static void handle_refs(struct ref_store *refs,
			struct rev_info *revs, unsigned flags,
			int (*for_each)(struct ref_store *, each_ref_fn, void *))
{
	struct all_refs_cb cb;

	if (!refs) {
		/* this could happen with uninitialized submodules */
		return;
	}

	init_all_refs_cb(&cb, revs, flags);
	for_each(refs, handle_one_ref, &cb);
}

static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
{
	struct all_refs_cb *cb = cb_data;
	if (!is_null_oid(oid)) {
		struct object *o = parse_object(cb->all_revs->repo, oid);
		if (o) {
			o->flags |= cb->all_flags;
			/* ??? CMDLINEFLAGS ??? */
			add_pending_object(cb->all_revs, o, "");
		}
		else if (!cb->warned_bad_reflog) {
			warning("reflog of '%s' references pruned commits",
				cb->name_for_errormsg);
			cb->warned_bad_reflog = 1;
		}
	}
}

static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
		const char *email, timestamp_t timestamp, int tz,
		const char *message, void *cb_data)
{
	handle_one_reflog_commit(ooid, cb_data);
	handle_one_reflog_commit(noid, cb_data);
	return 0;
}

static int handle_one_reflog(const char *refname_in_wt,
			     const struct object_id *oid,
			     int flag, void *cb_data)
{
	struct all_refs_cb *cb = cb_data;
	struct strbuf refname = STRBUF_INIT;

	cb->warned_bad_reflog = 0;
	strbuf_worktree_ref(cb->wt, &refname, refname_in_wt);
	cb->name_for_errormsg = refname.buf;
	refs_for_each_reflog_ent(get_main_ref_store(the_repository),
				 refname.buf,
				 handle_one_reflog_ent, cb_data);
	strbuf_release(&refname);
	return 0;
}

static void add_other_reflogs_to_pending(struct all_refs_cb *cb)
{
	struct worktree **worktrees, **p;

	worktrees = get_worktrees(0);
	for (p = worktrees; *p; p++) {
		struct worktree *wt = *p;

		if (wt->is_current)
			continue;

		cb->wt = wt;
		refs_for_each_reflog(get_worktree_ref_store(wt),
				     handle_one_reflog,
				     cb);
	}
	free_worktrees(worktrees);
}

void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
{
	struct all_refs_cb cb;

	cb.all_revs = revs;
	cb.all_flags = flags;
	cb.wt = NULL;
	for_each_reflog(handle_one_reflog, &cb);

	if (!revs->single_worktree)
		add_other_reflogs_to_pending(&cb);
}

static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
			   struct strbuf *path, unsigned int flags)
{
	size_t baselen = path->len;
	int i;

	if (it->entry_count >= 0) {
		struct tree *tree = lookup_tree(revs->repo, &it->oid);
		tree->object.flags |= flags;
		add_pending_object_with_path(revs, &tree->object, "",
					     040000, path->buf);
	}

	for (i = 0; i < it->subtree_nr; i++) {
		struct cache_tree_sub *sub = it->down[i];
		strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
		add_cache_tree(sub->cache_tree, revs, path, flags);
		strbuf_setlen(path, baselen);
	}

}

static void do_add_index_objects_to_pending(struct rev_info *revs,
					    struct index_state *istate,
					    unsigned int flags)
{
	int i;

	for (i = 0; i < istate->cache_nr; i++) {
		struct cache_entry *ce = istate->cache[i];
		struct blob *blob;

		if (S_ISGITLINK(ce->ce_mode))
			continue;

		blob = lookup_blob(revs->repo, &ce->oid);
		if (!blob)
			die("unable to add index blob to traversal");
		blob->object.flags |= flags;
		add_pending_object_with_path(revs, &blob->object, "",
					     ce->ce_mode, ce->name);
	}

	if (istate->cache_tree) {
		struct strbuf path = STRBUF_INIT;
		add_cache_tree(istate->cache_tree, revs, &path, flags);
		strbuf_release(&path);
	}
}

void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
{
	struct worktree **worktrees, **p;

	repo_read_index(revs->repo);
	do_add_index_objects_to_pending(revs, revs->repo->index, flags);

	if (revs->single_worktree)
		return;

	worktrees = get_worktrees(0);
	for (p = worktrees; *p; p++) {
		struct worktree *wt = *p;
		struct index_state istate = { NULL };

		if (wt->is_current)
			continue; /* current index already taken care of */

		if (read_index_from(&istate,
				    worktree_git_path(wt, "index"),
				    get_worktree_git_dir(wt)) > 0)
			do_add_index_objects_to_pending(revs, &istate, flags);
		discard_index(&istate);
	}
	free_worktrees(worktrees);
}

static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
			    int exclude_parent)
{
	struct object_id oid;
	struct object *it;
	struct commit *commit;
	struct commit_list *parents;
	int parent_number;
	const char *arg = arg_;

	if (*arg == '^') {
		flags ^= UNINTERESTING | BOTTOM;
		arg++;
	}
	if (get_oid_committish(arg, &oid))
		return 0;
	while (1) {
		it = get_reference(revs, arg, &oid, 0);
		if (!it && revs->ignore_missing)
			return 0;
		if (it->type != OBJ_TAG)
			break;
		if (!((struct tag*)it)->tagged)
			return 0;
		oidcpy(&oid, &((struct tag*)it)->tagged->oid);
	}
	if (it->type != OBJ_COMMIT)
		return 0;
	commit = (struct commit *)it;
	if (exclude_parent &&
	    exclude_parent > commit_list_count(commit->parents))
		return 0;
	for (parents = commit->parents, parent_number = 1;
	     parents;
	     parents = parents->next, parent_number++) {
		if (exclude_parent && parent_number != exclude_parent)
			continue;

		it = &parents->item->object;
		it->flags |= flags;
		add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
		add_pending_object(revs, it, arg);
	}
	return 1;
}

void repo_init_revisions(struct repository *r,
			 struct rev_info *revs,
			 const char *prefix)
{
	memset(revs, 0, sizeof(*revs));

	revs->repo = r;
	revs->abbrev = DEFAULT_ABBREV;
	revs->ignore_merges = 1;
	revs->simplify_history = 1;
	revs->pruning.repo = r;
	revs->pruning.flags.recursive = 1;
	revs->pruning.flags.quick = 1;
	revs->pruning.add_remove = file_add_remove;
	revs->pruning.change = file_change;
	revs->pruning.change_fn_data = revs;
	revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
	revs->dense = 1;
	revs->prefix = prefix;
	revs->max_age = -1;
	revs->min_age = -1;
	revs->skip_count = -1;
	revs->max_count = -1;
	revs->max_parents = -1;
	revs->expand_tabs_in_log = -1;

	revs->commit_format = CMIT_FMT_DEFAULT;
	revs->expand_tabs_in_log_default = 8;

	init_grep_defaults(revs->repo);
	grep_init(&revs->grep_filter, revs->repo, prefix);
	revs->grep_filter.status_only = 1;

	repo_diff_setup(revs->repo, &revs->diffopt);
	if (prefix && !revs->diffopt.prefix) {
		revs->diffopt.prefix = prefix;
		revs->diffopt.prefix_length = strlen(prefix);
	}

	revs->notes_opt.use_default_notes = -1;
}

static void add_pending_commit_list(struct rev_info *revs,
				    struct commit_list *commit_list,
				    unsigned int flags)
{
	while (commit_list) {
		struct object *object = &commit_list->item->object;
		object->flags |= flags;
		add_pending_object(revs, object, oid_to_hex(&object->oid));
		commit_list = commit_list->next;
	}
}

static void prepare_show_merge(struct rev_info *revs)
{
	struct commit_list *bases;
	struct commit *head, *other;
	struct object_id oid;
	const char **prune = NULL;
	int i, prune_num = 1; /* counting terminating NULL */
	struct index_state *istate = revs->repo->index;

	if (get_oid("HEAD", &oid))
		die("--merge without HEAD?");
	head = lookup_commit_or_die(&oid, "HEAD");
	if (get_oid("MERGE_HEAD", &oid))
		die("--merge without MERGE_HEAD?");
	other = lookup_commit_or_die(&oid, "MERGE_HEAD");
	add_pending_object(revs, &head->object, "HEAD");
	add_pending_object(revs, &other->object, "MERGE_HEAD");
	bases = get_merge_bases(head, other);
	add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
	add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
	free_commit_list(bases);
	head->object.flags |= SYMMETRIC_LEFT;

	if (!istate->cache_nr)
		repo_read_index(revs->repo);
	for (i = 0; i < istate->cache_nr; i++) {
		const struct cache_entry *ce = istate->cache[i];
		if (!ce_stage(ce))
			continue;
		if (ce_path_match(istate, ce, &revs->prune_data, NULL)) {
			prune_num++;
			REALLOC_ARRAY(prune, prune_num);
			prune[prune_num-2] = ce->name;
			prune[prune_num-1] = NULL;
		}
		while ((i+1 < istate->cache_nr) &&
		       ce_same_name(ce, istate->cache[i+1]))
			i++;
	}
	clear_pathspec(&revs->prune_data);
	parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
		       PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
	revs->limited = 1;
}

static int dotdot_missing(const char *arg, char *dotdot,
			  struct rev_info *revs, int symmetric)
{
	if (revs->ignore_missing)
		return 0;
	/* de-munge so we report the full argument */
	*dotdot = '.';
	die(symmetric
	    ? "Invalid symmetric difference expression %s"
	    : "Invalid revision range %s", arg);
}

static int handle_dotdot_1(const char *arg, char *dotdot,
			   struct rev_info *revs, int flags,
			   int cant_be_filename,
			   struct object_context *a_oc,
			   struct object_context *b_oc)
{
	const char *a_name, *b_name;
	struct object_id a_oid, b_oid;
	struct object *a_obj, *b_obj;
	unsigned int a_flags, b_flags;
	int symmetric = 0;
	unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
	unsigned int oc_flags = GET_OID_COMMITTISH | GET_OID_RECORD_PATH;

	a_name = arg;
	if (!*a_name)
		a_name = "HEAD";

	b_name = dotdot + 2;
	if (*b_name == '.') {
		symmetric = 1;
		b_name++;
	}
	if (!*b_name)
		b_name = "HEAD";

	if (get_oid_with_context(revs->repo, a_name, oc_flags, &a_oid, a_oc) ||
	    get_oid_with_context(revs->repo, b_name, oc_flags, &b_oid, b_oc))
		return -1;

	if (!cant_be_filename) {
		*dotdot = '.';
		verify_non_filename(revs->prefix, arg);
		*dotdot = '\0';
	}

	a_obj = parse_object(revs->repo, &a_oid);
	b_obj = parse_object(revs->repo, &b_oid);
	if (!a_obj || !b_obj)
		return dotdot_missing(arg, dotdot, revs, symmetric);

	if (!symmetric) {
		/* just A..B */
		b_flags = flags;
		a_flags = flags_exclude;
	} else {
		/* A...B -- find merge bases between the two */
		struct commit *a, *b;
		struct commit_list *exclude;

		a = lookup_commit_reference(revs->repo, &a_obj->oid);
		b = lookup_commit_reference(revs->repo, &b_obj->oid);
		if (!a || !b)
			return dotdot_missing(arg, dotdot, revs, symmetric);

		exclude = get_merge_bases(a, b);
		add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
				     flags_exclude);
		add_pending_commit_list(revs, exclude, flags_exclude);
		free_commit_list(exclude);

		b_flags = flags;
		a_flags = flags | SYMMETRIC_LEFT;
	}

	a_obj->flags |= a_flags;
	b_obj->flags |= b_flags;
	add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
	add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
	add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
	add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
	return 0;
}

static int handle_dotdot(const char *arg,
			 struct rev_info *revs, int flags,
			 int cant_be_filename)
{
	struct object_context a_oc, b_oc;
	char *dotdot = strstr(arg, "..");
	int ret;

	if (!dotdot)
		return -1;

	memset(&a_oc, 0, sizeof(a_oc));
	memset(&b_oc, 0, sizeof(b_oc));

	*dotdot = '\0';
	ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
			      &a_oc, &b_oc);
	*dotdot = '.';

	free(a_oc.path);
	free(b_oc.path);

	return ret;
}

int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
{
	struct object_context oc;
	char *mark;
	struct object *object;
	struct object_id oid;
	int local_flags;
	const char *arg = arg_;
	int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
	unsigned get_sha1_flags = GET_OID_RECORD_PATH;

	flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;

	if (!cant_be_filename && !strcmp(arg, "..")) {
		/*
		 * Just ".."?  That is not a range but the
		 * pathspec for the parent directory.
		 */
		return -1;
	}

	if (!handle_dotdot(arg, revs, flags, revarg_opt))
		return 0;

	mark = strstr(arg, "^@");
	if (mark && !mark[2]) {
		*mark = 0;
		if (add_parents_only(revs, arg, flags, 0))
			return 0;
		*mark = '^';
	}
	mark = strstr(arg, "^!");
	if (mark && !mark[2]) {
		*mark = 0;
		if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
			*mark = '^';
	}
	mark = strstr(arg, "^-");
	if (mark) {
		int exclude_parent = 1;

		if (mark[2]) {
			char *end;
			exclude_parent = strtoul(mark + 2, &end, 10);
			if (*end != '\0' || !exclude_parent)
				return -1;
		}

		*mark = 0;
		if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
			*mark = '^';
	}

	local_flags = 0;
	if (*arg == '^') {
		local_flags = UNINTERESTING | BOTTOM;
		arg++;
	}

	if (revarg_opt & REVARG_COMMITTISH)
		get_sha1_flags |= GET_OID_COMMITTISH;

	if (get_oid_with_context(revs->repo, arg, get_sha1_flags, &oid, &oc))
		return revs->ignore_missing ? 0 : -1;
	if (!cant_be_filename)
		verify_non_filename(revs->prefix, arg);
	object = get_reference(revs, arg, &oid, flags ^ local_flags);
	if (!object)
		return revs->ignore_missing ? 0 : -1;
	add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
	add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
	free(oc.path);
	return 0;
}

static void read_pathspec_from_stdin(struct strbuf *sb,
				     struct argv_array *prune)
{
	while (strbuf_getline(sb, stdin) != EOF)
		argv_array_push(prune, sb->buf);
}

static void read_revisions_from_stdin(struct rev_info *revs,
				      struct argv_array *prune)
{
	struct strbuf sb;
	int seen_dashdash = 0;
	int save_warning;

	save_warning = warn_on_object_refname_ambiguity;
	warn_on_object_refname_ambiguity = 0;

	strbuf_init(&sb, 1000);
	while (strbuf_getline(&sb, stdin) != EOF) {
		int len = sb.len;
		if (!len)
			break;
		if (sb.buf[0] == '-') {
			if (len == 2 && sb.buf[1] == '-') {
				seen_dashdash = 1;
				break;
			}
			die("options not supported in --stdin mode");
		}
		if (handle_revision_arg(sb.buf, revs, 0,
					REVARG_CANNOT_BE_FILENAME))
			die("bad revision '%s'", sb.buf);
	}
	if (seen_dashdash)
		read_pathspec_from_stdin(&sb, prune);

	strbuf_release(&sb);
	warn_on_object_refname_ambiguity = save_warning;
}

static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
{
	append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
}

static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
{
	append_header_grep_pattern(&revs->grep_filter, field, pattern);
}

static void add_message_grep(struct rev_info *revs, const char *pattern)
{
	add_grep(revs, pattern, GREP_PATTERN_BODY);
}

static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
			       int *unkc, const char **unkv,
			       const struct setup_revision_opt* opt)
{
	const char *arg = argv[0];
	const char *optarg;
	int argcount;
	const unsigned hexsz = the_hash_algo->hexsz;

	/* pseudo revision arguments */
	if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
	    !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
	    !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
	    !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
	    !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
	    !strcmp(arg, "--indexed-objects") ||
	    starts_with(arg, "--exclude=") ||
	    starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
	    starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
	{
		unkv[(*unkc)++] = arg;
		return 1;
	}

	if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
		revs->max_count = atoi(optarg);
		revs->no_walk = 0;
		return argcount;
	} else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
		revs->skip_count = atoi(optarg);
		return argcount;
	} else if ((*arg == '-') && isdigit(arg[1])) {
		/* accept -<digit>, like traditional "head" */
		if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
		    revs->max_count < 0)
			die("'%s': not a non-negative integer", arg + 1);
		revs->no_walk = 0;
	} else if (!strcmp(arg, "-n")) {
		if (argc <= 1)
			return error("-n requires an argument");
		revs->max_count = atoi(argv[1]);
		revs->no_walk = 0;
		return 2;
	} else if (skip_prefix(arg, "-n", &optarg)) {
		revs->max_count = atoi(optarg);
		revs->no_walk = 0;
	} else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
		revs->max_age = atoi(optarg);
		return argcount;
	} else if ((argcount = parse_long_opt("since", argv, &optarg))) {
		revs->max_age = approxidate(optarg);
		return argcount;
	} else if ((argcount = parse_long_opt("after", argv, &optarg))) {
		revs->max_age = approxidate(optarg);
		return argcount;
	} else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
		revs->min_age = atoi(optarg);
		return argcount;
	} else if ((argcount = parse_long_opt("before", argv, &optarg))) {
		revs->min_age = approxidate(optarg);
		return argcount;
	} else if ((argcount = parse_long_opt("until", argv, &optarg))) {
		revs->min_age = approxidate(optarg);
		return argcount;
	} else if (!strcmp(arg, "--first-parent")) {
		revs->first_parent_only = 1;
	} else if (!strcmp(arg, "--ancestry-path")) {
		revs->ancestry_path = 1;
		revs->simplify_history = 0;
		revs->limited = 1;
	} else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
		init_reflog_walk(&revs->reflog_info);
	} else if (!strcmp(arg, "--default")) {
		if (argc <= 1)
			return error("bad --default argument");
		revs->def = argv[1];
		return 2;
	} else if (!strcmp(arg, "--merge")) {
		revs->show_merge = 1;
	} else if (!strcmp(arg, "--topo-order")) {
		revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
		revs->topo_order = 1;
	} else if (!strcmp(arg, "--simplify-merges")) {
		revs->simplify_merges = 1;
		revs->topo_order = 1;
		revs->rewrite_parents = 1;
		revs->simplify_history = 0;
		revs->limited = 1;
	} else if (!strcmp(arg, "--simplify-by-decoration")) {
		revs->simplify_merges = 1;
		revs->topo_order = 1;
		revs->rewrite_parents = 1;
		revs->simplify_history = 0;
		revs->simplify_by_decoration = 1;
		revs->limited = 1;
		revs->prune = 1;
		load_ref_decorations(NULL, DECORATE_SHORT_REFS);
	} else if (!strcmp(arg, "--date-order")) {
		revs->sort_order = REV_SORT_BY_COMMIT_DATE;
		revs->topo_order = 1;
	} else if (!strcmp(arg, "--author-date-order")) {
		revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
		revs->topo_order = 1;
	} else if (!strcmp(arg, "--early-output")) {
		revs->early_output = 100;
		revs->topo_order = 1;
	} else if (skip_prefix(arg, "--early-output=", &optarg)) {
		if (strtoul_ui(optarg, 10, &revs->early_output) < 0)
			die("'%s': not a non-negative integer", optarg);
		revs->topo_order = 1;
	} else if (!strcmp(arg, "--parents")) {
		revs->rewrite_parents = 1;
		revs->print_parents = 1;
	} else if (!strcmp(arg, "--dense")) {
		revs->dense = 1;
	} else if (!strcmp(arg, "--sparse")) {
		revs->dense = 0;
	} else if (!strcmp(arg, "--in-commit-order")) {
		revs->tree_blobs_in_commit_order = 1;
	} else if (!strcmp(arg, "--remove-empty")) {
		revs->remove_empty_trees = 1;
	} else if (!strcmp(arg, "--merges")) {
		revs->min_parents = 2;
	} else if (!strcmp(arg, "--no-merges")) {
		revs->max_parents = 1;
	} else if (skip_prefix(arg, "--min-parents=", &optarg)) {
		revs->min_parents = atoi(optarg);
	} else if (!strcmp(arg, "--no-min-parents")) {
		revs->min_parents = 0;
	} else if (skip_prefix(arg, "--max-parents=", &optarg)) {
		revs->max_parents = atoi(optarg);
	} else if (!strcmp(arg, "--no-max-parents")) {
		revs->max_parents = -1;
	} else if (!strcmp(arg, "--boundary")) {
		revs->boundary = 1;
	} else if (!strcmp(arg, "--left-right")) {
		revs->left_right = 1;
	} else if (!strcmp(arg, "--left-only")) {
		if (revs->right_only)
			die("--left-only is incompatible with --right-only"
			    " or --cherry");
		revs->left_only = 1;
	} else if (!strcmp(arg, "--right-only")) {
		if (revs->left_only)
			die("--right-only is incompatible with --left-only");
		revs->right_only = 1;
	} else if (!strcmp(arg, "--cherry")) {
		if (revs->left_only)
			die("--cherry is incompatible with --left-only");
		revs->cherry_mark = 1;
		revs->right_only = 1;
		revs->max_parents = 1;
		revs->limited = 1;
	} else if (!strcmp(arg, "--count")) {
		revs->count = 1;
	} else if (!strcmp(arg, "--cherry-mark")) {
		if (revs->cherry_pick)
			die("--cherry-mark is incompatible with --cherry-pick");
		revs->cherry_mark = 1;
		revs->limited = 1; /* needs limit_list() */
	} else if (!strcmp(arg, "--cherry-pick")) {
		if (revs->cherry_mark)
			die("--cherry-pick is incompatible with --cherry-mark");
		revs->cherry_pick = 1;
		revs->limited = 1;
	} else if (!strcmp(arg, "--objects")) {
		revs->tag_objects = 1;
		revs->tree_objects = 1;
		revs->blob_objects = 1;
	} else if (!strcmp(arg, "--objects-edge")) {
		revs->tag_objects = 1;
		revs->tree_objects = 1;
		revs->blob_objects = 1;
		revs->edge_hint = 1;
	} else if (!strcmp(arg, "--objects-edge-aggressive")) {
		revs->tag_objects = 1;
		revs->tree_objects = 1;
		revs->blob_objects = 1;
		revs->edge_hint = 1;
		revs->edge_hint_aggressive = 1;
	} else if (!strcmp(arg, "--verify-objects")) {
		revs->tag_objects = 1;
		revs->tree_objects = 1;
		revs->blob_objects = 1;
		revs->verify_objects = 1;
	} else if (!strcmp(arg, "--unpacked")) {
		revs->unpacked = 1;
	} else if (starts_with(arg, "--unpacked=")) {
		die("--unpacked=<packfile> no longer supported.");
	} else if (!strcmp(arg, "-r")) {
		revs->diff = 1;
		revs->diffopt.flags.recursive = 1;
	} else if (!strcmp(arg, "-t")) {
		revs->diff = 1;
		revs->diffopt.flags.recursive = 1;
		revs->diffopt.flags.tree_in_recursive = 1;
	} else if (!strcmp(arg, "-m")) {
		revs->ignore_merges = 0;
	} else if (!strcmp(arg, "-c")) {
		revs->diff = 1;
		revs->dense_combined_merges = 0;
		revs->combine_merges = 1;
	} else if (!strcmp(arg, "--combined-all-paths")) {
		revs->diff = 1;
		revs->combined_all_paths = 1;
	} else if (!strcmp(arg, "--cc")) {
		revs->diff = 1;
		revs->dense_combined_merges = 1;
		revs->combine_merges = 1;
	} else if (!strcmp(arg, "-v")) {
		revs->verbose_header = 1;
	} else if (!strcmp(arg, "--pretty")) {
		revs->verbose_header = 1;
		revs->pretty_given = 1;
		get_commit_format(NULL, revs);
	} else if (skip_prefix(arg, "--pretty=", &optarg) ||
		   skip_prefix(arg, "--format=", &optarg)) {
		/*
		 * Detached form ("--pretty X" as opposed to "--pretty=X")
		 * not allowed, since the argument is optional.
		 */
		revs->verbose_header = 1;
		revs->pretty_given = 1;
		get_commit_format(optarg, revs);
	} else if (!strcmp(arg, "--expand-tabs")) {
		revs->expand_tabs_in_log = 8;
	} else if (!strcmp(arg, "--no-expand-tabs")) {
		revs->expand_tabs_in_log = 0;
	} else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
		int val;
		if (strtol_i(arg, 10, &val) < 0 || val < 0)
			die("'%s': not a non-negative integer", arg);
		revs->expand_tabs_in_log = val;
	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
		revs->show_notes = 1;
		revs->show_notes_given = 1;
		revs->notes_opt.use_default_notes = 1;
	} else if (!strcmp(arg, "--show-signature")) {
		revs->show_signature = 1;
	} else if (!strcmp(arg, "--no-show-signature")) {
		revs->show_signature = 0;
	} else if (!strcmp(arg, "--show-linear-break")) {
		revs->break_bar = "                    ..........";
		revs->track_linear = 1;
		revs->track_first_time = 1;
	} else if (skip_prefix(arg, "--show-linear-break=", &optarg)) {
		revs->break_bar = xstrdup(optarg);
		revs->track_linear = 1;
		revs->track_first_time = 1;
	} else if (skip_prefix(arg, "--show-notes=", &optarg) ||
		   skip_prefix(arg, "--notes=", &optarg)) {
		struct strbuf buf = STRBUF_INIT;
		revs->show_notes = 1;
		revs->show_notes_given = 1;
		if (starts_with(arg, "--show-notes=") &&
		    revs->notes_opt.use_default_notes < 0)
			revs->notes_opt.use_default_notes = 1;
		strbuf_addstr(&buf, optarg);
		expand_notes_ref(&buf);
		string_list_append(&revs->notes_opt.extra_notes_refs,
				   strbuf_detach(&buf, NULL));
	} else if (!strcmp(arg, "--no-notes")) {
		revs->show_notes = 0;
		revs->show_notes_given = 1;
		revs->notes_opt.use_default_notes = -1;
		/* we have been strdup'ing ourselves, so trick
		 * string_list into free()ing strings */
		revs->notes_opt.extra_notes_refs.strdup_strings = 1;
		string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
		revs->notes_opt.extra_notes_refs.strdup_strings = 0;
	} else if (!strcmp(arg, "--standard-notes")) {
		revs->show_notes_given = 1;
		revs->notes_opt.use_default_notes = 1;
	} else if (!strcmp(arg, "--no-standard-notes")) {
		revs->notes_opt.use_default_notes = 0;
	} else if (!strcmp(arg, "--oneline")) {
		revs->verbose_header = 1;
		get_commit_format("oneline", revs);
		revs->pretty_given = 1;
		revs->abbrev_commit = 1;
	} else if (!strcmp(arg, "--graph")) {
		revs->topo_order = 1;
		revs->rewrite_parents = 1;
		revs->graph = graph_init(revs);
	} else if (!strcmp(arg, "--root")) {
		revs->show_root_diff = 1;
	} else if (!strcmp(arg, "--no-commit-id")) {
		revs->no_commit_id = 1;
	} else if (!strcmp(arg, "--always")) {
		revs->always_show_header = 1;
	} else if (!strcmp(arg, "--no-abbrev")) {
		revs->abbrev = 0;
	} else if (!strcmp(arg, "--abbrev")) {
		revs->abbrev = DEFAULT_ABBREV;
	} else if (skip_prefix(arg, "--abbrev=", &optarg)) {
		revs->abbrev = strtoul(optarg, NULL, 10);
		if (revs->abbrev < MINIMUM_ABBREV)
			revs->abbrev = MINIMUM_ABBREV;
		else if (revs->abbrev > hexsz)
			revs->abbrev = hexsz;
	} else if (!strcmp(arg, "--abbrev-commit")) {
		revs->abbrev_commit = 1;
		revs->abbrev_commit_given = 1;
	} else if (!strcmp(arg, "--no-abbrev-commit")) {
		revs->abbrev_commit = 0;
	} else if (!strcmp(arg, "--full-diff")) {
		revs->diff = 1;
		revs->full_diff = 1;
	} else if (!strcmp(arg, "--full-history")) {
		revs->simplify_history = 0;
	} else if (!strcmp(arg, "--relative-date")) {
		revs->date_mode.type = DATE_RELATIVE;
		revs->date_mode_explicit = 1;
	} else if ((argcount = parse_long_opt("date", argv, &optarg))) {
		parse_date_format(optarg, &revs->date_mode);
		revs->date_mode_explicit = 1;
		return argcount;
	} else if (!strcmp(arg, "--log-size")) {
		revs->show_log_size = 1;
	}
	/*
	 * Grepping the commit log
	 */
	else if ((argcount = parse_long_opt("author", argv, &optarg))) {
		add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
		return argcount;
	} else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
		add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
		return argcount;
	} else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
		add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
		return argcount;
	} else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
		add_message_grep(revs, optarg);
		return argcount;
	} else if (!strcmp(arg, "--grep-debug")) {
		revs->grep_filter.debug = 1;
	} else if (!strcmp(arg, "--basic-regexp")) {
		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
	} else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
	} else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
		revs->grep_filter.ignore_case = 1;
		revs->diffopt.pickaxe_opts |= DIFF_PICKAXE_IGNORE_CASE;
	} else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
	} else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
	} else if (!strcmp(arg, "--all-match")) {
		revs->grep_filter.all_match = 1;
	} else if (!strcmp(arg, "--invert-grep")) {
		revs->invert_grep = 1;
	} else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
		if (strcmp(optarg, "none"))
			git_log_output_encoding = xstrdup(optarg);
		else
			git_log_output_encoding = "";
		return argcount;
	} else if (!strcmp(arg, "--reverse")) {
		revs->reverse ^= 1;
	} else if (!strcmp(arg, "--children")) {
		revs->children.name = "children";
		revs->limited = 1;
	} else if (!strcmp(arg, "--ignore-missing")) {
		revs->ignore_missing = 1;
	} else if (opt && opt->allow_exclude_promisor_objects &&
		   !strcmp(arg, "--exclude-promisor-objects")) {
		if (fetch_if_missing)
			BUG("exclude_promisor_objects can only be used when fetch_if_missing is 0");
		revs->exclude_promisor_objects = 1;
	} else {
		int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
		if (!opts)
			unkv[(*unkc)++] = arg;
		return opts;
	}
	if (revs->graph && revs->track_linear)
		die("--show-linear-break and --graph are incompatible");

	return 1;
}

void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
			const struct option *options,
			const char * const usagestr[])
{
	int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
				    &ctx->cpidx, ctx->out, NULL);
	if (n <= 0) {
		error("unknown option `%s'", ctx->argv[0]);
		usage_with_options(usagestr, options);
	}
	ctx->argv += n;
	ctx->argc -= n;
}

static int for_each_bisect_ref(struct ref_store *refs, each_ref_fn fn,
			       void *cb_data, const char *term)
{
	struct strbuf bisect_refs = STRBUF_INIT;
	int status;
	strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
	status = refs_for_each_fullref_in(refs, bisect_refs.buf, fn, cb_data, 0);
	strbuf_release(&bisect_refs);
	return status;
}

static int for_each_bad_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
{
	return for_each_bisect_ref(refs, fn, cb_data, term_bad);
}

static int for_each_good_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
{
	return for_each_bisect_ref(refs, fn, cb_data, term_good);
}

static int handle_revision_pseudo_opt(const char *submodule,
				struct rev_info *revs,
				int argc, const char **argv, int *flags)
{
	const char *arg = argv[0];
	const char *optarg;
	struct ref_store *refs;
	int argcount;

	if (submodule) {
		/*
		 * We need some something like get_submodule_worktrees()
		 * before we can go through all worktrees of a submodule,
		 * .e.g with adding all HEADs from --all, which is not
		 * supported right now, so stick to single worktree.
		 */
		if (!revs->single_worktree)
			BUG("--single-worktree cannot be used together with submodule");
		refs = get_submodule_ref_store(submodule);
	} else
		refs = get_main_ref_store(revs->repo);

	/*
	 * NOTE!
	 *
	 * Commands like "git shortlog" will not accept the options below
	 * unless parse_revision_opt queues them (as opposed to erroring
	 * out).
	 *
	 * When implementing your new pseudo-option, remember to
	 * register it in the list at the top of handle_revision_opt.
	 */
	if (!strcmp(arg, "--all")) {
		handle_refs(refs, revs, *flags, refs_for_each_ref);
		handle_refs(refs, revs, *flags, refs_head_ref);
		if (!revs->single_worktree) {
			struct all_refs_cb cb;

			init_all_refs_cb(&cb, revs, *flags);
			other_head_refs(handle_one_ref, &cb);
		}
		clear_ref_exclusion(&revs->ref_excludes);
	} else if (!strcmp(arg, "--branches")) {
		handle_refs(refs, revs, *flags, refs_for_each_branch_ref);
		clear_ref_exclusion(&revs->ref_excludes);
	} else if (!strcmp(arg, "--bisect")) {
		read_bisect_terms(&term_bad, &term_good);
		handle_refs(refs, revs, *flags, for_each_bad_bisect_ref);
		handle_refs(refs, revs, *flags ^ (UNINTERESTING | BOTTOM),
			    for_each_good_bisect_ref);
		revs->bisect = 1;
	} else if (!strcmp(arg, "--tags")) {
		handle_refs(refs, revs, *flags, refs_for_each_tag_ref);
		clear_ref_exclusion(&revs->ref_excludes);
	} else if (!strcmp(arg, "--remotes")) {
		handle_refs(refs, revs, *flags, refs_for_each_remote_ref);
		clear_ref_exclusion(&revs->ref_excludes);
	} else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
		struct all_refs_cb cb;
		init_all_refs_cb(&cb, revs, *flags);
		for_each_glob_ref(handle_one_ref, optarg, &cb);
		clear_ref_exclusion(&revs->ref_excludes);
		return argcount;
	} else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
		add_ref_exclusion(&revs->ref_excludes, optarg);
		return argcount;
	} else if (skip_prefix(arg, "--branches=", &optarg)) {
		struct all_refs_cb cb;
		init_all_refs_cb(&cb, revs, *flags);
		for_each_glob_ref_in(handle_one_ref, optarg, "refs/heads/", &cb);
		clear_ref_exclusion(&revs->ref_excludes);
	} else if (skip_prefix(arg, "--tags=", &optarg)) {
		struct all_refs_cb cb;
		init_all_refs_cb(&cb, revs, *flags);
		for_each_glob_ref_in(handle_one_ref, optarg, "refs/tags/", &cb);
		clear_ref_exclusion(&revs->ref_excludes);
	} else if (skip_prefix(arg, "--remotes=", &optarg)) {
		struct all_refs_cb cb;
		init_all_refs_cb(&cb, revs, *flags);
		for_each_glob_ref_in(handle_one_ref, optarg, "refs/remotes/", &cb);
		clear_ref_exclusion(&revs->ref_excludes);
	} else if (!strcmp(arg, "--reflog")) {
		add_reflogs_to_pending(revs, *flags);
	} else if (!strcmp(arg, "--indexed-objects")) {
		add_index_objects_to_pending(revs, *flags);
	} else if (!strcmp(arg, "--not")) {
		*flags ^= UNINTERESTING | BOTTOM;
	} else if (!strcmp(arg, "--no-walk")) {
		revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
	} else if (skip_prefix(arg, "--no-walk=", &optarg)) {
		/*
		 * Detached form ("--no-walk X" as opposed to "--no-walk=X")
		 * not allowed, since the argument is optional.
		 */
		if (!strcmp(optarg, "sorted"))
			revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
		else if (!strcmp(optarg, "unsorted"))
			revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
		else
			return error("invalid argument to --no-walk");
	} else if (!strcmp(arg, "--do-walk")) {
		revs->no_walk = 0;
	} else if (!strcmp(arg, "--single-worktree")) {
		revs->single_worktree = 1;
	} else {
		return 0;
	}

	return 1;
}

static void NORETURN diagnose_missing_default(const char *def)
{
	int flags;
	const char *refname;

	refname = resolve_ref_unsafe(def, 0, NULL, &flags);
	if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
		die(_("your current branch appears to be broken"));

	skip_prefix(refname, "refs/heads/", &refname);
	die(_("your current branch '%s' does not have any commits yet"),
	    refname);
}

/*
 * Parse revision information, filling in the "rev_info" structure,
 * and removing the used arguments from the argument list.
 *
 * Returns the number of arguments left that weren't recognized
 * (which are also moved to the head of the argument list)
 */
int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
{
	int i, flags, left, seen_dashdash, got_rev_arg = 0, revarg_opt;
	struct argv_array prune_data = ARGV_ARRAY_INIT;
	const char *submodule = NULL;

	if (opt)
		submodule = opt->submodule;

	/* First, search for "--" */
	if (opt && opt->assume_dashdash) {
		seen_dashdash = 1;
	} else {
		seen_dashdash = 0;
		for (i = 1; i < argc; i++) {
			const char *arg = argv[i];
			if (strcmp(arg, "--"))
				continue;
			argv[i] = NULL;
			argc = i;
			if (argv[i + 1])
				argv_array_pushv(&prune_data, argv + i + 1);
			seen_dashdash = 1;
			break;
		}
	}

	/* Second, deal with arguments and options */
	flags = 0;
	revarg_opt = opt ? opt->revarg_opt : 0;
	if (seen_dashdash)
		revarg_opt |= REVARG_CANNOT_BE_FILENAME;
	for (left = i = 1; i < argc; i++) {
		const char *arg = argv[i];
		if (*arg == '-') {
			int opts;

			opts = handle_revision_pseudo_opt(submodule,
						revs, argc - i, argv + i,
						&flags);
			if (opts > 0) {
				i += opts - 1;
				continue;
			}

			if (!strcmp(arg, "--stdin")) {
				if (revs->disable_stdin) {
					argv[left++] = arg;
					continue;
				}
				if (revs->read_from_stdin++)
					die("--stdin given twice?");
				read_revisions_from_stdin(revs, &prune_data);
				continue;
			}

			opts = handle_revision_opt(revs, argc - i, argv + i,
						   &left, argv, opt);
			if (opts > 0) {
				i += opts - 1;
				continue;
			}
			if (opts < 0)
				exit(128);
			continue;
		}


		if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
			int j;
			if (seen_dashdash || *arg == '^')
				die("bad revision '%s'", arg);

			/* If we didn't have a "--":
			 * (1) all filenames must exist;
			 * (2) all rev-args must not be interpretable
			 *     as a valid filename.
			 * but the latter we have checked in the main loop.
			 */
			for (j = i; j < argc; j++)
				verify_filename(revs->prefix, argv[j], j == i);

			argv_array_pushv(&prune_data, argv + i);
			break;
		}
		else
			got_rev_arg = 1;
	}

	if (prune_data.argc) {
		/*
		 * If we need to introduce the magic "a lone ':' means no
		 * pathspec whatsoever", here is the place to do so.
		 *
		 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
		 *	prune_data.nr = 0;
		 *	prune_data.alloc = 0;
		 *	free(prune_data.path);
		 *	prune_data.path = NULL;
		 * } else {
		 *	terminate prune_data.alloc with NULL and
		 *	call init_pathspec() to set revs->prune_data here.
		 * }
		 */
		parse_pathspec(&revs->prune_data, 0, 0,
			       revs->prefix, prune_data.argv);
	}
	argv_array_clear(&prune_data);

	if (revs->def == NULL)
		revs->def = opt ? opt->def : NULL;
	if (opt && opt->tweak)
		opt->tweak(revs, opt);
	if (revs->show_merge)
		prepare_show_merge(revs);
	if (revs->def && !revs->pending.nr && !revs->rev_input_given && !got_rev_arg) {
		struct object_id oid;
		struct object *object;
		struct object_context oc;
		if (get_oid_with_context(revs->repo, revs->def, 0, &oid, &oc))
			diagnose_missing_default(revs->def);
		object = get_reference(revs, revs->def, &oid, 0);
		add_pending_object_with_mode(revs, object, revs->def, oc.mode);
	}

	/* Did the user ask for any diff output? Run the diff! */
	if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
		revs->diff = 1;

	/* Pickaxe, diff-filter and rename following need diffs */
	if ((revs->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
	    revs->diffopt.filter ||
	    revs->diffopt.flags.follow_renames)
		revs->diff = 1;

	if (revs->diffopt.objfind)
		revs->simplify_history = 0;

	if (revs->topo_order && !generation_numbers_enabled(the_repository))
		revs->limited = 1;

	if (revs->prune_data.nr) {
		copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
		/* Can't prune commits with rename following: the paths change.. */
		if (!revs->diffopt.flags.follow_renames)
			revs->prune = 1;
		if (!revs->full_diff)
			copy_pathspec(&revs->diffopt.pathspec,
				      &revs->prune_data);
	}
	if (revs->combine_merges)
		revs->ignore_merges = 0;
	if (revs->combined_all_paths && !revs->combine_merges)
		die("--combined-all-paths makes no sense without -c or --cc");

	revs->diffopt.abbrev = revs->abbrev;

	if (revs->line_level_traverse) {
		revs->limited = 1;
		revs->topo_order = 1;
	}

	diff_setup_done(&revs->diffopt);

	grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
				 &revs->grep_filter);
	compile_grep_patterns(&revs->grep_filter);

	if (revs->reverse && revs->reflog_info)
		die("cannot combine --reverse with --walk-reflogs");
	if (revs->reflog_info && revs->limited)
		die("cannot combine --walk-reflogs with history-limiting options");
	if (revs->rewrite_parents && revs->children.name)
		die("cannot combine --parents and --children");

	/*
	 * Limitations on the graph functionality
	 */
	if (revs->reverse && revs->graph)
		die("cannot combine --reverse with --graph");

	if (revs->reflog_info && revs->graph)
		die("cannot combine --walk-reflogs with --graph");
	if (revs->no_walk && revs->graph)
		die("cannot combine --no-walk with --graph");
	if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
		die("cannot use --grep-reflog without --walk-reflogs");

	if (revs->first_parent_only && revs->bisect)
		die(_("--first-parent is incompatible with --bisect"));

	if (revs->line_level_traverse &&
	    (revs->diffopt.output_format & ~(DIFF_FORMAT_PATCH | DIFF_FORMAT_NO_OUTPUT)))
		die(_("-L does not yet support diff formats besides -p and -s"));

	if (revs->expand_tabs_in_log < 0)
		revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;

	return left;
}

static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
{
	struct commit_list *l = xcalloc(1, sizeof(*l));

	l->item = child;
	l->next = add_decoration(&revs->children, &parent->object, l);
}

static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
{
	struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
	struct commit_list **pp, *p;
	int surviving_parents;

	/* Examine existing parents while marking ones we have seen... */
	pp = &commit->parents;
	surviving_parents = 0;
	while ((p = *pp) != NULL) {
		struct commit *parent = p->item;
		if (parent->object.flags & TMP_MARK) {
			*pp = p->next;
			if (ts)
				compact_treesame(revs, commit, surviving_parents);
			continue;
		}
		parent->object.flags |= TMP_MARK;
		surviving_parents++;
		pp = &p->next;
	}
	/* clear the temporary mark */
	for (p = commit->parents; p; p = p->next) {
		p->item->object.flags &= ~TMP_MARK;
	}
	/* no update_treesame() - removing duplicates can't affect TREESAME */
	return surviving_parents;
}

struct merge_simplify_state {
	struct commit *simplified;
};

static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
{
	struct merge_simplify_state *st;

	st = lookup_decoration(&revs->merge_simplification, &commit->object);
	if (!st) {
		st = xcalloc(1, sizeof(*st));
		add_decoration(&revs->merge_simplification, &commit->object, st);
	}
	return st;
}

static int mark_redundant_parents(struct commit *commit)
{
	struct commit_list *h = reduce_heads(commit->parents);
	int i = 0, marked = 0;
	struct commit_list *po, *pn;

	/* Want these for sanity-checking only */
	int orig_cnt = commit_list_count(commit->parents);
	int cnt = commit_list_count(h);

	/*
	 * Not ready to remove items yet, just mark them for now, based
	 * on the output of reduce_heads(). reduce_heads outputs the reduced
	 * set in its original order, so this isn't too hard.
	 */
	po = commit->parents;
	pn = h;
	while (po) {
		if (pn && po->item == pn->item) {
			pn = pn->next;
			i++;
		} else {
			po->item->object.flags |= TMP_MARK;
			marked++;
		}
		po=po->next;
	}

	if (i != cnt || cnt+marked != orig_cnt)
		die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);

	free_commit_list(h);

	return marked;
}

static int mark_treesame_root_parents(struct commit *commit)
{
	struct commit_list *p;
	int marked = 0;

	for (p = commit->parents; p; p = p->next) {
		struct commit *parent = p->item;
		if (!parent->parents && (parent->object.flags & TREESAME)) {
			parent->object.flags |= TMP_MARK;
			marked++;
		}
	}

	return marked;
}

/*
 * Awkward naming - this means one parent we are TREESAME to.
 * cf mark_treesame_root_parents: root parents that are TREESAME (to an
 * empty tree). Better name suggestions?
 */
static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
{
	struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
	struct commit *unmarked = NULL, *marked = NULL;
	struct commit_list *p;
	unsigned n;

	for (p = commit->parents, n = 0; p; p = p->next, n++) {
		if (ts->treesame[n]) {
			if (p->item->object.flags & TMP_MARK) {
				if (!marked)
					marked = p->item;
			} else {
				if (!unmarked) {
					unmarked = p->item;
					break;
				}
			}
		}
	}

	/*
	 * If we are TREESAME to a marked-for-deletion parent, but not to any
	 * unmarked parents, unmark the first TREESAME parent. This is the
	 * parent that the default simplify_history==1 scan would have followed,
	 * and it doesn't make sense to omit that path when asking for a
	 * simplified full history. Retaining it improves the chances of
	 * understanding odd missed merges that took an old version of a file.
	 *
	 * Example:
	 *
	 *   I--------*X       A modified the file, but mainline merge X used
	 *    \       /        "-s ours", so took the version from I. X is
	 *     `-*A--'         TREESAME to I and !TREESAME to A.
	 *
	 * Default log from X would produce "I". Without this check,
	 * --full-history --simplify-merges would produce "I-A-X", showing
	 * the merge commit X and that it changed A, but not making clear that
	 * it had just taken the I version. With this check, the topology above
	 * is retained.
	 *
	 * Note that it is possible that the simplification chooses a different
	 * TREESAME parent from the default, in which case this test doesn't
	 * activate, and we _do_ drop the default parent. Example:
	 *
	 *   I------X         A modified the file, but it was reverted in B,
	 *    \    /          meaning mainline merge X is TREESAME to both
	 *    *A-*B           parents.
	 *
	 * Default log would produce "I" by following the first parent;
	 * --full-history --simplify-merges will produce "I-A-B". But this is a
	 * reasonable result - it presents a logical full history leading from
	 * I to X, and X is not an important merge.
	 */
	if (!unmarked && marked) {
		marked->object.flags &= ~TMP_MARK;
		return 1;
	}

	return 0;
}

static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
{
	struct commit_list **pp, *p;
	int nth_parent, removed = 0;

	pp = &commit->parents;
	nth_parent = 0;
	while ((p = *pp) != NULL) {
		struct commit *parent = p->item;
		if (parent->object.flags & TMP_MARK) {
			parent->object.flags &= ~TMP_MARK;
			*pp = p->next;
			free(p);
			removed++;
			compact_treesame(revs, commit, nth_parent);
			continue;
		}
		pp = &p->next;
		nth_parent++;
	}

	/* Removing parents can only increase TREESAMEness */
	if (removed && !(commit->object.flags & TREESAME))
		update_treesame(revs, commit);

	return nth_parent;
}

static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
{
	struct commit_list *p;
	struct commit *parent;
	struct merge_simplify_state *st, *pst;
	int cnt;

	st = locate_simplify_state(revs, commit);

	/*
	 * Have we handled this one?
	 */
	if (st->simplified)
		return tail;

	/*
	 * An UNINTERESTING commit simplifies to itself, so does a
	 * root commit.  We do not rewrite parents of such commit
	 * anyway.
	 */
	if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
		st->simplified = commit;
		return tail;
	}

	/*
	 * Do we know what commit all of our parents that matter
	 * should be rewritten to?  Otherwise we are not ready to
	 * rewrite this one yet.
	 */
	for (cnt = 0, p = commit->parents; p; p = p->next) {
		pst = locate_simplify_state(revs, p->item);
		if (!pst->simplified) {
			tail = &commit_list_insert(p->item, tail)->next;
			cnt++;
		}
		if (revs->first_parent_only)
			break;
	}
	if (cnt) {
		tail = &commit_list_insert(commit, tail)->next;
		return tail;
	}

	/*
	 * Rewrite our list of parents. Note that this cannot
	 * affect our TREESAME flags in any way - a commit is
	 * always TREESAME to its simplification.
	 */
	for (p = commit->parents; p; p = p->next) {
		pst = locate_simplify_state(revs, p->item);
		p->item = pst->simplified;
		if (revs->first_parent_only)
			break;
	}

	if (revs->first_parent_only)
		cnt = 1;
	else
		cnt = remove_duplicate_parents(revs, commit);

	/*
	 * It is possible that we are a merge and one side branch
	 * does not have any commit that touches the given paths;
	 * in such a case, the immediate parent from that branch
	 * will be rewritten to be the merge base.
	 *
	 *      o----X		X: the commit we are looking at;
	 *     /    /		o: a commit that touches the paths;
	 * ---o----'
	 *
	 * Further, a merge of an independent branch that doesn't
	 * touch the path will reduce to a treesame root parent:
	 *
	 *  ----o----X		X: the commit we are looking at;
	 *          /		o: a commit that touches the paths;
	 *         r		r: a root commit not touching the paths
	 *
	 * Detect and simplify both cases.
	 */
	if (1 < cnt) {
		int marked = mark_redundant_parents(commit);
		marked += mark_treesame_root_parents(commit);
		if (marked)
			marked -= leave_one_treesame_to_parent(revs, commit);
		if (marked)
			cnt = remove_marked_parents(revs, commit);
	}

	/*
	 * A commit simplifies to itself if it is a root, if it is
	 * UNINTERESTING, if it touches the given paths, or if it is a
	 * merge and its parents don't simplify to one relevant commit
	 * (the first two cases are already handled at the beginning of
	 * this function).
	 *
	 * Otherwise, it simplifies to what its sole relevant parent
	 * simplifies to.
	 */
	if (!cnt ||
	    (commit->object.flags & UNINTERESTING) ||
	    !(commit->object.flags & TREESAME) ||
	    (parent = one_relevant_parent(revs, commit->parents)) == NULL)
		st->simplified = commit;
	else {
		pst = locate_simplify_state(revs, parent);
		st->simplified = pst->simplified;
	}
	return tail;
}

static void simplify_merges(struct rev_info *revs)
{
	struct commit_list *list, *next;
	struct commit_list *yet_to_do, **tail;
	struct commit *commit;

	if (!revs->prune)
		return;

	/* feed the list reversed */
	yet_to_do = NULL;
	for (list = revs->commits; list; list = next) {
		commit = list->item;
		next = list->next;
		/*
		 * Do not free(list) here yet; the original list
		 * is used later in this function.
		 */
		commit_list_insert(commit, &yet_to_do);
	}
	while (yet_to_do) {
		list = yet_to_do;
		yet_to_do = NULL;
		tail = &yet_to_do;
		while (list) {
			commit = pop_commit(&list);
			tail = simplify_one(revs, commit, tail);
		}
	}

	/* clean up the result, removing the simplified ones */
	list = revs->commits;
	revs->commits = NULL;
	tail = &revs->commits;
	while (list) {
		struct merge_simplify_state *st;

		commit = pop_commit(&list);
		st = locate_simplify_state(revs, commit);
		if (st->simplified == commit)
			tail = &commit_list_insert(commit, tail)->next;
	}
}

static void set_children(struct rev_info *revs)
{
	struct commit_list *l;
	for (l = revs->commits; l; l = l->next) {
		struct commit *commit = l->item;
		struct commit_list *p;

		for (p = commit->parents; p; p = p->next)
			add_child(revs, p->item, commit);
	}
}

void reset_revision_walk(void)
{
	clear_object_flags(SEEN | ADDED | SHOWN);
}

static int mark_uninteresting(const struct object_id *oid,
			      struct packed_git *pack,
			      uint32_t pos,
			      void *cb)
{
	struct rev_info *revs = cb;
	struct object *o = parse_object(revs->repo, oid);
	o->flags |= UNINTERESTING | SEEN;
	return 0;
}

define_commit_slab(indegree_slab, int);
define_commit_slab(author_date_slab, timestamp_t);

struct topo_walk_info {
	uint32_t min_generation;
	struct prio_queue explore_queue;
	struct prio_queue indegree_queue;
	struct prio_queue topo_queue;
	struct indegree_slab indegree;
	struct author_date_slab author_date;
};

static inline void test_flag_and_insert(struct prio_queue *q, struct commit *c, int flag)
{
	if (c->object.flags & flag)
		return;

	c->object.flags |= flag;
	prio_queue_put(q, c);
}

static void explore_walk_step(struct rev_info *revs)
{
	struct topo_walk_info *info = revs->topo_walk_info;
	struct commit_list *p;
	struct commit *c = prio_queue_get(&info->explore_queue);

	if (!c)
		return;

	if (parse_commit_gently(c, 1) < 0)
		return;

	if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
		record_author_date(&info->author_date, c);

	if (revs->max_age != -1 && (c->date < revs->max_age))
		c->object.flags |= UNINTERESTING;

	if (process_parents(revs, c, NULL, NULL) < 0)
		return;

	if (c->object.flags & UNINTERESTING)
		mark_parents_uninteresting(c);

	for (p = c->parents; p; p = p->next)
		test_flag_and_insert(&info->explore_queue, p->item, TOPO_WALK_EXPLORED);
}

static void explore_to_depth(struct rev_info *revs,
			     uint32_t gen_cutoff)
{
	struct topo_walk_info *info = revs->topo_walk_info;
	struct commit *c;
	while ((c = prio_queue_peek(&info->explore_queue)) &&
	       c->generation >= gen_cutoff)
		explore_walk_step(revs);
}

static void indegree_walk_step(struct rev_info *revs)
{
	struct commit_list *p;
	struct topo_walk_info *info = revs->topo_walk_info;
	struct commit *c = prio_queue_get(&info->indegree_queue);

	if (!c)
		return;

	if (parse_commit_gently(c, 1) < 0)
		return;

	explore_to_depth(revs, c->generation);

	for (p = c->parents; p; p = p->next) {
		struct commit *parent = p->item;
		int *pi = indegree_slab_at(&info->indegree, parent);

		if (*pi)
			(*pi)++;
		else
			*pi = 2;

		test_flag_and_insert(&info->indegree_queue, parent, TOPO_WALK_INDEGREE);

		if (revs->first_parent_only)
			return;
	}
}

static void compute_indegrees_to_depth(struct rev_info *revs,
				       uint32_t gen_cutoff)
{
	struct topo_walk_info *info = revs->topo_walk_info;
	struct commit *c;
	while ((c = prio_queue_peek(&info->indegree_queue)) &&
	       c->generation >= gen_cutoff)
		indegree_walk_step(revs);
}

static void init_topo_walk(struct rev_info *revs)
{
	struct topo_walk_info *info;
	struct commit_list *list;
	revs->topo_walk_info = xmalloc(sizeof(struct topo_walk_info));
	info = revs->topo_walk_info;
	memset(info, 0, sizeof(struct topo_walk_info));

	init_indegree_slab(&info->indegree);
	memset(&info->explore_queue, 0, sizeof(info->explore_queue));
	memset(&info->indegree_queue, 0, sizeof(info->indegree_queue));
	memset(&info->topo_queue, 0, sizeof(info->topo_queue));

	switch (revs->sort_order) {
	default: /* REV_SORT_IN_GRAPH_ORDER */
		info->topo_queue.compare = NULL;
		break;
	case REV_SORT_BY_COMMIT_DATE:
		info->topo_queue.compare = compare_commits_by_commit_date;
		break;
	case REV_SORT_BY_AUTHOR_DATE:
		init_author_date_slab(&info->author_date);
		info->topo_queue.compare = compare_commits_by_author_date;
		info->topo_queue.cb_data = &info->author_date;
		break;
	}

	info->explore_queue.compare = compare_commits_by_gen_then_commit_date;
	info->indegree_queue.compare = compare_commits_by_gen_then_commit_date;

	info->min_generation = GENERATION_NUMBER_INFINITY;
	for (list = revs->commits; list; list = list->next) {
		struct commit *c = list->item;

		if (parse_commit_gently(c, 1))
			continue;

		test_flag_and_insert(&info->explore_queue, c, TOPO_WALK_EXPLORED);
		test_flag_and_insert(&info->indegree_queue, c, TOPO_WALK_INDEGREE);

		if (c->generation < info->min_generation)
			info->min_generation = c->generation;

		*(indegree_slab_at(&info->indegree, c)) = 1;

		if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
			record_author_date(&info->author_date, c);
	}
	compute_indegrees_to_depth(revs, info->min_generation);

	for (list = revs->commits; list; list = list->next) {
		struct commit *c = list->item;

		if (*(indegree_slab_at(&info->indegree, c)) == 1)
			prio_queue_put(&info->topo_queue, c);
	}

	/*
	 * This is unfortunate; the initial tips need to be shown
	 * in the order given from the revision traversal machinery.
	 */
	if (revs->sort_order == REV_SORT_IN_GRAPH_ORDER)
		prio_queue_reverse(&info->topo_queue);
}

static struct commit *next_topo_commit(struct rev_info *revs)
{
	struct commit *c;
	struct topo_walk_info *info = revs->topo_walk_info;

	/* pop next off of topo_queue */
	c = prio_queue_get(&info->topo_queue);

	if (c)
		*(indegree_slab_at(&info->indegree, c)) = 0;

	return c;
}

static void expand_topo_walk(struct rev_info *revs, struct commit *commit)
{
	struct commit_list *p;
	struct topo_walk_info *info = revs->topo_walk_info;
	if (process_parents(revs, commit, NULL, NULL) < 0) {
		if (!revs->ignore_missing_links)
			die("Failed to traverse parents of commit %s",
			    oid_to_hex(&commit->object.oid));
	}

	for (p = commit->parents; p; p = p->next) {
		struct commit *parent = p->item;
		int *pi;

		if (parse_commit_gently(parent, 1) < 0)
			continue;

		if (parent->generation < info->min_generation) {
			info->min_generation = parent->generation;
			compute_indegrees_to_depth(revs, info->min_generation);
		}

		pi = indegree_slab_at(&info->indegree, parent);

		(*pi)--;
		if (*pi == 1)
			prio_queue_put(&info->topo_queue, parent);

		if (revs->first_parent_only)
			return;
	}
}

int prepare_revision_walk(struct rev_info *revs)
{
	int i;
	struct object_array old_pending;
	struct commit_list **next = &revs->commits;

	memcpy(&old_pending, &revs->pending, sizeof(old_pending));
	revs->pending.nr = 0;
	revs->pending.alloc = 0;
	revs->pending.objects = NULL;
	for (i = 0; i < old_pending.nr; i++) {
		struct object_array_entry *e = old_pending.objects + i;
		struct commit *commit = handle_commit(revs, e);
		if (commit) {
			if (!(commit->object.flags & SEEN)) {
				commit->object.flags |= SEEN;
				next = commit_list_append(commit, next);
			}
		}
	}
	object_array_clear(&old_pending);

	/* Signal whether we need per-parent treesame decoration */
	if (revs->simplify_merges ||
	    (revs->limited && limiting_can_increase_treesame(revs)))
		revs->treesame.name = "treesame";

	if (revs->exclude_promisor_objects) {
		for_each_packed_object(mark_uninteresting, revs,
				       FOR_EACH_OBJECT_PROMISOR_ONLY);
	}

	if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
		commit_list_sort_by_date(&revs->commits);
	if (revs->no_walk)
		return 0;
	if (revs->limited) {
		if (limit_list(revs) < 0)
			return -1;
		if (revs->topo_order)
			sort_in_topological_order(&revs->commits, revs->sort_order);
	} else if (revs->topo_order)
		init_topo_walk(revs);
	if (revs->line_level_traverse)
		line_log_filter(revs);
	if (revs->simplify_merges)
		simplify_merges(revs);
	if (revs->children.name)
		set_children(revs);
	return 0;
}

static enum rewrite_result rewrite_one_1(struct rev_info *revs,
					 struct commit **pp,
					 struct prio_queue *queue)
{
	for (;;) {
		struct commit *p = *pp;
		if (!revs->limited)
			if (process_parents(revs, p, NULL, queue) < 0)
				return rewrite_one_error;
		if (p->object.flags & UNINTERESTING)
			return rewrite_one_ok;
		if (!(p->object.flags & TREESAME))
			return rewrite_one_ok;
		if (!p->parents)
			return rewrite_one_noparents;
		if ((p = one_relevant_parent(revs, p->parents)) == NULL)
			return rewrite_one_ok;
		*pp = p;
	}
}

static void merge_queue_into_list(struct prio_queue *q, struct commit_list **list)
{
	while (q->nr) {
		struct commit *item = prio_queue_peek(q);
		struct commit_list *p = *list;

		if (p && p->item->date >= item->date)
			list = &p->next;
		else {
			p = commit_list_insert(item, list);
			list = &p->next; /* skip newly added item */
			prio_queue_get(q); /* pop item */
		}
	}
}

static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
{
	struct prio_queue queue = { compare_commits_by_commit_date };
	enum rewrite_result ret = rewrite_one_1(revs, pp, &queue);
	merge_queue_into_list(&queue, &revs->commits);
	clear_prio_queue(&queue);
	return ret;
}

int rewrite_parents(struct rev_info *revs, struct commit *commit,
	rewrite_parent_fn_t rewrite_parent)
{
	struct commit_list **pp = &commit->parents;
	while (*pp) {
		struct commit_list *parent = *pp;
		switch (rewrite_parent(revs, &parent->item)) {
		case rewrite_one_ok:
			break;
		case rewrite_one_noparents:
			*pp = parent->next;
			continue;
		case rewrite_one_error:
			return -1;
		}
		pp = &parent->next;
	}
	remove_duplicate_parents(revs, commit);
	return 0;
}

static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
{
	char *person, *endp;
	size_t len, namelen, maillen;
	const char *name;
	const char *mail;
	struct ident_split ident;

	person = strstr(buf->buf, what);
	if (!person)
		return 0;

	person += strlen(what);
	endp = strchr(person, '\n');
	if (!endp)
		return 0;

	len = endp - person;

	if (split_ident_line(&ident, person, len))
		return 0;

	mail = ident.mail_begin;
	maillen = ident.mail_end - ident.mail_begin;
	name = ident.name_begin;
	namelen = ident.name_end - ident.name_begin;

	if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
		struct strbuf namemail = STRBUF_INIT;

		strbuf_addf(&namemail, "%.*s <%.*s>",
			    (int)namelen, name, (int)maillen, mail);

		strbuf_splice(buf, ident.name_begin - buf->buf,
			      ident.mail_end - ident.name_begin + 1,
			      namemail.buf, namemail.len);

		strbuf_release(&namemail);

		return 1;
	}

	return 0;
}

static int commit_match(struct commit *commit, struct rev_info *opt)
{
	int retval;
	const char *encoding;
	const char *message;
	struct strbuf buf = STRBUF_INIT;

	if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
		return 1;

	/* Prepend "fake" headers as needed */
	if (opt->grep_filter.use_reflog_filter) {
		strbuf_addstr(&buf, "reflog ");
		get_reflog_message(&buf, opt->reflog_info);
		strbuf_addch(&buf, '\n');
	}

	/*
	 * We grep in the user's output encoding, under the assumption that it
	 * is the encoding they are most likely to write their grep pattern
	 * for. In addition, it means we will match the "notes" encoding below,
	 * so we will not end up with a buffer that has two different encodings
	 * in it.
	 */
	encoding = get_log_output_encoding();
	message = logmsg_reencode(commit, NULL, encoding);

	/* Copy the commit to temporary if we are using "fake" headers */
	if (buf.len)
		strbuf_addstr(&buf, message);

	if (opt->grep_filter.header_list && opt->mailmap) {
		if (!buf.len)
			strbuf_addstr(&buf, message);

		commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
		commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
	}

	/* Append "fake" message parts as needed */
	if (opt->show_notes) {
		if (!buf.len)
			strbuf_addstr(&buf, message);
		format_display_notes(&commit->object.oid, &buf, encoding, 1);
	}

	/*
	 * Find either in the original commit message, or in the temporary.
	 * Note that we cast away the constness of "message" here. It is
	 * const because it may come from the cached commit buffer. That's OK,
	 * because we know that it is modifiable heap memory, and that while
	 * grep_buffer may modify it for speed, it will restore any
	 * changes before returning.
	 */
	if (buf.len)
		retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
	else
		retval = grep_buffer(&opt->grep_filter,
				     (char *)message, strlen(message));
	strbuf_release(&buf);
	unuse_commit_buffer(commit, message);
	return opt->invert_grep ? !retval : retval;
}

static inline int want_ancestry(const struct rev_info *revs)
{
	return (revs->rewrite_parents || revs->children.name);
}

/*
 * Return a timestamp to be used for --since/--until comparisons for this
 * commit, based on the revision options.
 */
static timestamp_t comparison_date(const struct rev_info *revs,
				   struct commit *commit)
{
	return revs->reflog_info ?
		get_reflog_timestamp(revs->reflog_info) :
		commit->date;
}

enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
{
	if (commit->object.flags & SHOWN)
		return commit_ignore;
	if (revs->unpacked && has_object_pack(&commit->object.oid))
		return commit_ignore;
	if (commit->object.flags & UNINTERESTING)
		return commit_ignore;
	if (revs->min_age != -1 &&
	    comparison_date(revs, commit) > revs->min_age)
			return commit_ignore;
	if (revs->min_parents || (revs->max_parents >= 0)) {
		int n = commit_list_count(commit->parents);
		if ((n < revs->min_parents) ||
		    ((revs->max_parents >= 0) && (n > revs->max_parents)))
			return commit_ignore;
	}
	if (!commit_match(commit, revs))
		return commit_ignore;
	if (revs->prune && revs->dense) {
		/* Commit without changes? */
		if (commit->object.flags & TREESAME) {
			int n;
			struct commit_list *p;
			/* drop merges unless we want parenthood */
			if (!want_ancestry(revs))
				return commit_ignore;
			/*
			 * If we want ancestry, then need to keep any merges
			 * between relevant commits to tie together topology.
			 * For consistency with TREESAME and simplification
			 * use "relevant" here rather than just INTERESTING,
			 * to treat bottom commit(s) as part of the topology.
			 */
			for (n = 0, p = commit->parents; p; p = p->next)
				if (relevant_commit(p->item))
					if (++n >= 2)
						return commit_show;
			return commit_ignore;
		}
	}
	return commit_show;
}

define_commit_slab(saved_parents, struct commit_list *);

#define EMPTY_PARENT_LIST ((struct commit_list *)-1)

/*
 * You may only call save_parents() once per commit (this is checked
 * for non-root commits).
 */
static void save_parents(struct rev_info *revs, struct commit *commit)
{
	struct commit_list **pp;

	if (!revs->saved_parents_slab) {
		revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
		init_saved_parents(revs->saved_parents_slab);
	}

	pp = saved_parents_at(revs->saved_parents_slab, commit);

	/*
	 * When walking with reflogs, we may visit the same commit
	 * several times: once for each appearance in the reflog.
	 *
	 * In this case, save_parents() will be called multiple times.
	 * We want to keep only the first set of parents.  We need to
	 * store a sentinel value for an empty (i.e., NULL) parent
	 * list to distinguish it from a not-yet-saved list, however.
	 */
	if (*pp)
		return;
	if (commit->parents)
		*pp = copy_commit_list(commit->parents);
	else
		*pp = EMPTY_PARENT_LIST;
}

static void free_saved_parents(struct rev_info *revs)
{
	if (revs->saved_parents_slab)
		clear_saved_parents(revs->saved_parents_slab);
}

struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
{
	struct commit_list *parents;

	if (!revs->saved_parents_slab)
		return commit->parents;

	parents = *saved_parents_at(revs->saved_parents_slab, commit);
	if (parents == EMPTY_PARENT_LIST)
		return NULL;
	return parents;
}

enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
{
	enum commit_action action = get_commit_action(revs, commit);

	if (action == commit_show &&
	    revs->prune && revs->dense && want_ancestry(revs)) {
		/*
		 * --full-diff on simplified parents is no good: it
		 * will show spurious changes from the commits that
		 * were elided.  So we save the parents on the side
		 * when --full-diff is in effect.
		 */
		if (revs->full_diff)
			save_parents(revs, commit);
		if (rewrite_parents(revs, commit, rewrite_one) < 0)
			return commit_error;
	}
	return action;
}

static void track_linear(struct rev_info *revs, struct commit *commit)
{
	if (revs->track_first_time) {
		revs->linear = 1;
		revs->track_first_time = 0;
	} else {
		struct commit_list *p;
		for (p = revs->previous_parents; p; p = p->next)
			if (p->item == NULL || /* first commit */
			    oideq(&p->item->object.oid, &commit->object.oid))
				break;
		revs->linear = p != NULL;
	}
	if (revs->reverse) {
		if (revs->linear)
			commit->object.flags |= TRACK_LINEAR;
	}
	free_commit_list(revs->previous_parents);
	revs->previous_parents = copy_commit_list(commit->parents);
}

static struct commit *get_revision_1(struct rev_info *revs)
{
	while (1) {
		struct commit *commit;

		if (revs->reflog_info)
			commit = next_reflog_entry(revs->reflog_info);
		else if (revs->topo_walk_info)
			commit = next_topo_commit(revs);
		else
			commit = pop_commit(&revs->commits);

		if (!commit)
			return NULL;

		if (revs->reflog_info)
			commit->object.flags &= ~(ADDED | SEEN | SHOWN);

		/*
		 * If we haven't done the list limiting, we need to look at
		 * the parents here. We also need to do the date-based limiting
		 * that we'd otherwise have done in limit_list().
		 */
		if (!revs->limited) {
			if (revs->max_age != -1 &&
			    comparison_date(revs, commit) < revs->max_age)
				continue;

			if (revs->reflog_info)
				try_to_simplify_commit(revs, commit);
			else if (revs->topo_walk_info)
				expand_topo_walk(revs, commit);
			else if (process_parents(revs, commit, &revs->commits, NULL) < 0) {
				if (!revs->ignore_missing_links)
					die("Failed to traverse parents of commit %s",
						oid_to_hex(&commit->object.oid));
			}
		}

		switch (simplify_commit(revs, commit)) {
		case commit_ignore:
			continue;
		case commit_error:
			die("Failed to simplify parents of commit %s",
			    oid_to_hex(&commit->object.oid));
		default:
			if (revs->track_linear)
				track_linear(revs, commit);
			return commit;
		}
	}
}

/*
 * Return true for entries that have not yet been shown.  (This is an
 * object_array_each_func_t.)
 */
static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
{
	return !(entry->item->flags & SHOWN);
}

/*
 * If array is on the verge of a realloc, garbage-collect any entries
 * that have already been shown to try to free up some space.
 */
static void gc_boundary(struct object_array *array)
{
	if (array->nr == array->alloc)
		object_array_filter(array, entry_unshown, NULL);
}

static void create_boundary_commit_list(struct rev_info *revs)
{
	unsigned i;
	struct commit *c;
	struct object_array *array = &revs->boundary_commits;
	struct object_array_entry *objects = array->objects;

	/*
	 * If revs->commits is non-NULL at this point, an error occurred in
	 * get_revision_1().  Ignore the error and continue printing the
	 * boundary commits anyway.  (This is what the code has always
	 * done.)
	 */
	if (revs->commits) {
		free_commit_list(revs->commits);
		revs->commits = NULL;
	}

	/*
	 * Put all of the actual boundary commits from revs->boundary_commits
	 * into revs->commits
	 */
	for (i = 0; i < array->nr; i++) {
		c = (struct commit *)(objects[i].item);
		if (!c)
			continue;
		if (!(c->object.flags & CHILD_SHOWN))
			continue;
		if (c->object.flags & (SHOWN | BOUNDARY))
			continue;
		c->object.flags |= BOUNDARY;
		commit_list_insert(c, &revs->commits);
	}

	/*
	 * If revs->topo_order is set, sort the boundary commits
	 * in topological order
	 */
	sort_in_topological_order(&revs->commits, revs->sort_order);
}

static struct commit *get_revision_internal(struct rev_info *revs)
{
	struct commit *c = NULL;
	struct commit_list *l;

	if (revs->boundary == 2) {
		/*
		 * All of the normal commits have already been returned,
		 * and we are now returning boundary commits.
		 * create_boundary_commit_list() has populated
		 * revs->commits with the remaining commits to return.
		 */
		c = pop_commit(&revs->commits);
		if (c)
			c->object.flags |= SHOWN;
		return c;
	}

	/*
	 * If our max_count counter has reached zero, then we are done. We
	 * don't simply return NULL because we still might need to show
	 * boundary commits. But we want to avoid calling get_revision_1, which
	 * might do a considerable amount of work finding the next commit only
	 * for us to throw it away.
	 *
	 * If it is non-zero, then either we don't have a max_count at all
	 * (-1), or it is still counting, in which case we decrement.
	 */
	if (revs->max_count) {
		c = get_revision_1(revs);
		if (c) {
			while (revs->skip_count > 0) {
				revs->skip_count--;
				c = get_revision_1(revs);
				if (!c)
					break;
			}
		}

		if (revs->max_count > 0)
			revs->max_count--;
	}

	if (c)
		c->object.flags |= SHOWN;

	if (!revs->boundary)
		return c;

	if (!c) {
		/*
		 * get_revision_1() runs out the commits, and
		 * we are done computing the boundaries.
		 * switch to boundary commits output mode.
		 */
		revs->boundary = 2;

		/*
		 * Update revs->commits to contain the list of
		 * boundary commits.
		 */
		create_boundary_commit_list(revs);

		return get_revision_internal(revs);
	}

	/*
	 * boundary commits are the commits that are parents of the
	 * ones we got from get_revision_1() but they themselves are
	 * not returned from get_revision_1().  Before returning
	 * 'c', we need to mark its parents that they could be boundaries.
	 */

	for (l = c->parents; l; l = l->next) {
		struct object *p;
		p = &(l->item->object);
		if (p->flags & (CHILD_SHOWN | SHOWN))
			continue;
		p->flags |= CHILD_SHOWN;
		gc_boundary(&revs->boundary_commits);
		add_object_array(p, NULL, &revs->boundary_commits);
	}

	return c;
}

struct commit *get_revision(struct rev_info *revs)
{
	struct commit *c;
	struct commit_list *reversed;

	if (revs->reverse) {
		reversed = NULL;
		while ((c = get_revision_internal(revs)))
			commit_list_insert(c, &reversed);
		revs->commits = reversed;
		revs->reverse = 0;
		revs->reverse_output_stage = 1;
	}

	if (revs->reverse_output_stage) {
		c = pop_commit(&revs->commits);
		if (revs->track_linear)
			revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
		return c;
	}

	c = get_revision_internal(revs);
	if (c && revs->graph)
		graph_update(revs->graph, c);
	if (!c) {
		free_saved_parents(revs);
		if (revs->previous_parents) {
			free_commit_list(revs->previous_parents);
			revs->previous_parents = NULL;
		}
	}
	return c;
}

char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
{
	if (commit->object.flags & BOUNDARY)
		return "-";
	else if (commit->object.flags & UNINTERESTING)
		return "^";
	else if (commit->object.flags & PATCHSAME)
		return "=";
	else if (!revs || revs->left_right) {
		if (commit->object.flags & SYMMETRIC_LEFT)
			return "<";
		else
			return ">";
	} else if (revs->graph)
		return "*";
	else if (revs->cherry_mark)
		return "+";
	return "";
}

void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
{
	char *mark = get_revision_mark(revs, commit);
	if (!strlen(mark))
		return;
	fputs(mark, stdout);
	putchar(' ');
}