Merge 10.3 into 10.4

In main.index_merge_myisam we remove the test that was added in
commit a2d24def8cc42d27c72d833abfb39ef24a2b96ba because
it duplicates the test case that was added in
commit 5af12e463549e4bbc2ce6ab720d78937d5e5db4e.

1 files changed, 22 insertions, 11 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 0528dfcadc6..899d1fc9782 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -1,5 +1,5 @@
 /* Copyright (c) 2000, 2015, Oracle and/or its affiliates.
-   Copyright (c) 2008, 2019, MariaDB
+   Copyright (c) 2008, 2020, MariaDB
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -357,7 +357,8 @@ QUICK_RANGE_SELECT *get_quick_select(PARAM *param,uint index,
 static TRP_RANGE *get_key_scans_params(PARAM *param, SEL_TREE *tree,
                                        bool index_read_must_be_used,
                                        bool update_tbl_stats,
-                                       double read_time);
+                                       double read_time,
+                                       bool ror_scans_required);
 static
 TRP_INDEX_INTERSECT *get_best_index_intersect(PARAM *param, SEL_TREE *tree,
                                               double read_time);
@@ -2637,7 +2638,7 @@ static int fill_used_fields_bitmap(PARAM *param)
      force_quick_range is really needed.
 
   RETURN
-   -1 if impossible select (i.e. certainly no rows will be selected)
+   -1 if error or impossible select (i.e. certainly no rows will be selected)
     0 if can't use quick_select
     1 if found usable ranges and quick select has been successfully created.
 */
@@ -2737,7 +2738,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
     {
       thd->no_errors=0;
       free_root(&alloc,MYF(0));			// Return memory & allocator
-      DBUG_RETURN(0);				// Can't use range
+      DBUG_RETURN(-1);				// Error
     }
     key_parts= param.key_parts;
 
@@ -2805,7 +2806,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
     {
       thd->no_errors=0;
       free_root(&alloc,MYF(0));			// Return memory & allocator
-      DBUG_RETURN(0);				// Can't use range
+      DBUG_RETURN(-1);				// Error
     }
 
     thd->mem_root= &alloc;
@@ -2861,6 +2862,13 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
           tree= NULL;
         }
       }
+      else if (thd->is_error())
+      {
+        thd->no_errors=0;
+        thd->mem_root= param.old_root;
+        free_root(&alloc, MYF(0));
+        DBUG_RETURN(-1);
+      }
     }
 
     /*
@@ -2910,7 +2918,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
       /* Get best 'range' plan and prepare data for making other plans */
       if ((range_trp= get_key_scans_params(&param, tree,
                                            only_single_index_range_scan, TRUE,
-                                           best_read_time)))
+                                           best_read_time, FALSE)))
       {
         best_trp= range_trp;
         best_read_time= best_trp->read_cost;
@@ -5078,7 +5086,8 @@ TABLE_READ_PLAN *get_best_disjunct_quick(PARAM *param, SEL_IMERGE *imerge,
     DBUG_EXECUTE("info", print_sel_tree(param, *ptree, &(*ptree)->keys_map,
                                         "tree in SEL_IMERGE"););
     Json_writer_object trace_idx(thd);
-    if (!(*cur_child= get_key_scans_params(param, *ptree, TRUE, FALSE, read_time)))
+    if (!(*cur_child= get_key_scans_params(param, *ptree, TRUE, FALSE,
+                                           read_time, TRUE)))
     {
       /*
         One of index scans in this index_merge is more expensive than entire
@@ -5440,7 +5449,7 @@ TABLE_READ_PLAN *merge_same_index_scans(PARAM *param, SEL_IMERGE *imerge,
          index merge retrievals are not well calibrated
     */
     trp= get_key_scans_params(param, *imerge->trees, FALSE, TRUE,
-                              read_time);
+                              read_time, TRUE);
   }
 
   DBUG_RETURN(trp); 
@@ -7324,6 +7333,7 @@ TRP_ROR_INTERSECT *get_best_covering_ror_intersect(PARAM *param,
       index_read_must_be_used if TRUE, assume 'index only' option will be set
                              (except for clustered PK indexes)
       read_time    don't create read plans with cost > read_time.
+      ror_scans_required           set to TRUE for index merge
   RETURN
     Best range read plan
     NULL if no plan found or error occurred
@@ -7332,7 +7342,8 @@ TRP_ROR_INTERSECT *get_best_covering_ror_intersect(PARAM *param,
 static TRP_RANGE *get_key_scans_params(PARAM *param, SEL_TREE *tree,
                                        bool index_read_must_be_used, 
                                        bool update_tbl_stats,
-                                       double read_time)
+                                       double read_time,
+                                       bool ror_scans_required)
 {
   uint idx, UNINIT_VAR(best_idx);
   SEL_ARG *key_to_read= NULL;
@@ -7386,7 +7397,7 @@ static TRP_RANGE *get_key_scans_params(PARAM *param, SEL_TREE *tree,
       found_records= check_quick_select(param, idx, read_index_only, key,
                                         update_tbl_stats, &mrr_flags,
                                         &buf_size, &cost, &is_ror_scan);
-      if (!is_ror_scan &&
+      if (ror_scans_required && !is_ror_scan &&
           !optimizer_flag(param->thd, OPTIMIZER_SWITCH_INDEX_MERGE_SORT_UNION))
         continue;
 
@@ -9773,7 +9784,7 @@ key_and(RANGE_OPT_PARAM *param, SEL_ARG *key1, SEL_ARG *key2, uint clone_flag)
       if (key2->next_key_part)
       {
 	key1->use_count--;			// Incremented in and_all_keys
-	return and_all_keys(param, key1, key2, clone_flag);
+        return and_all_keys(param, key1, key2->next_key_part, clone_flag);
       }
       key2->use_count--;			// Key2 doesn't have a tree
     }