patch 8.1.0956: using context:0 in 'diffopt' does not work wellv8.1.0956

Problem:    Using context:0 in 'diffopt' does not work well.
Solution:   Make zero context do the same as one line context. (closes #4005)

6 files changed, 74 insertions, 1 deletions

diff --git a/src/diff.c b/src/diff.c
index 9220c7214..336157c6d 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -2277,7 +2277,7 @@ diffopt_changed(void)
 	    tp->tp_diff_invalid = TRUE;
 
     diff_flags = diff_flags_new;
-    diff_context = diff_context_new;
+    diff_context = diff_context_new == 0 ? 1 : diff_context_new;
     diff_foldcolumn = diff_foldcolumn_new;
     diff_algorithm = diff_algorithm_new;
 
diff --git a/src/testdir/dumps/Test_diff_06.0.dump b/src/testdir/dumps/Test_diff_06.0.dump
new file mode 100644
index 000000000..8d7308978
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_06.0.dump
@@ -0,0 +1,20 @@
+|++0#0000e05#a8a8a8255| >+|-@1| @1|3| |l|i|n|e|s|:| |1|-@19||+1#0000000#ffffff0|++0#0000e05#a8a8a8255| |+|-@1| @1|3| |l|i|n|e|s|:| |1|-@19
+| @1|4+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|4+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|4+0#0000000#5fd7ff255| @33||+1&#ffffff0| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34
+| +0#0000e05#a8a8a8255@1|5+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|5+0#0000000#ffffff0| @33
+|++0#0000e05#a8a8a8255| |+|-@1| @1|4| |l|i|n|e|s|:| |6|-@19||+1#0000000#ffffff0|++0#0000e05#a8a8a8255| |+|-@1| @1|4| |l|i|n|e|s|:| |6|-@19
+| @1|1+0#0000000#ffffff0|0| @32||+1&&| +0#0000e05#a8a8a8255@1|1+0#0000000#ffffff0|0| @32
+| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1|1+0#0000000#5fd7ff255@1| @32
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+|X+3#0000000&|f|i|l|e|1| @12|1|,|1| @11|A|l@1| |X+1&&|f|i|l|e|2| @12|1|,|1| @11|A|l@1
+|:+0&&|s|e|t| |d|i|f@1|o|p|t|+|=|c|o|n|t|e|x|t|:|0| @51
diff --git a/src/testdir/dumps/Test_diff_06.1.dump b/src/testdir/dumps/Test_diff_06.1.dump
new file mode 100644
index 000000000..b2b658328
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_06.1.dump
@@ -0,0 +1,20 @@
+|++0#0000e05#a8a8a8255| >+|-@1| @1|3| |l|i|n|e|s|:| |1|-@19||+1#0000000#ffffff0|++0#0000e05#a8a8a8255| |+|-@1| @1|3| |l|i|n|e|s|:| |1|-@19
+| @1|4+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|4+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|4+0#0000000#5fd7ff255| @33||+1&#ffffff0| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34
+| +0#0000e05#a8a8a8255@1|5+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|5+0#0000000#ffffff0| @33
+|++0#0000e05#a8a8a8255| |+|-@1| @1|4| |l|i|n|e|s|:| |6|-@19||+1#0000000#ffffff0|++0#0000e05#a8a8a8255| |+|-@1| @1|4| |l|i|n|e|s|:| |6|-@19
+| @1|1+0#0000000#ffffff0|0| @32||+1&&| +0#0000e05#a8a8a8255@1|1+0#0000000#ffffff0|0| @32
+| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1|1+0#0000000#5fd7ff255@1| @32
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+|X+3#0000000&|f|i|l|e|1| @12|1|,|1| @11|A|l@1| |X+1&&|f|i|l|e|2| @12|1|,|1| @11|A|l@1
+|:+0&&|s|e|t| |d|i|f@1|o|p|t|+|=|c|o|n|t|e|x|t|:|1| @51
diff --git a/src/testdir/dumps/Test_diff_06.2.dump b/src/testdir/dumps/Test_diff_06.2.dump
new file mode 100644
index 000000000..ce07d07d7
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_06.2.dump
@@ -0,0 +1,20 @@
+|++0#0000e05#a8a8a8255| >+|-@1| @1|2| |l|i|n|e|s|:| |1|-@19||+1#0000000#ffffff0|++0#0000e05#a8a8a8255| |+|-@1| @1|2| |l|i|n|e|s|:| |1|-@19
+| @1|3+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|3+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|4+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|4+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|4+0#0000000#5fd7ff255| @33||+1&#ffffff0| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34
+| +0#0000e05#a8a8a8255@1|5+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|5+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|6+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|6+0#0000000#ffffff0| @33
+|++0#0000e05#a8a8a8255| |+|-@1| @1|2| |l|i|n|e|s|:| |7|-@19||+1#0000000#ffffff0|++0#0000e05#a8a8a8255| |+|-@1| @1|2| |l|i|n|e|s|:| |7|-@19
+| @1|9+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|9+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|1+0#0000000#ffffff0|0| @32||+1&&| +0#0000e05#a8a8a8255@1|1+0#0000000#ffffff0|0| @32
+| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1|1+0#0000000#5fd7ff255@1| @32
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+|X+3#0000000&|f|i|l|e|1| @12|1|,|1| @11|A|l@1| |X+1&&|f|i|l|e|2| @12|1|,|1| @11|A|l@1
+|:+0&&@1|s|e|t| |d|i|f@1|o|p|t|+|=|c|o|n|t|e|x|t|:|2| @50
diff --git a/src/testdir/test_diffmode.vim b/src/testdir/test_diffmode.vim
index 84fb4519c..5a3a6beee 100644
--- a/src/testdir/test_diffmode.vim
+++ b/src/testdir/test_diffmode.vim
@@ -783,6 +783,17 @@ func Test_diff_screen()
   call WriteDiffFiles(buf, [1, 2, 3, 4, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])
   call VerifyBoth(buf, 'Test_diff_06', '')
 
+  " Variants on test 6 with different context settings
+  call term_sendkeys(buf, ":set diffopt+=context:2\<cr>")
+  call VerifyScreenDump(buf, 'Test_diff_06.2', {})
+  call term_sendkeys(buf, ":set diffopt-=context:2\<cr>")
+  call term_sendkeys(buf, ":set diffopt+=context:1\<cr>")
+  call VerifyScreenDump(buf, 'Test_diff_06.1', {})
+  call term_sendkeys(buf, ":set diffopt-=context:1\<cr>")
+  call term_sendkeys(buf, ":set diffopt+=context:0\<cr>")
+  call VerifyScreenDump(buf, 'Test_diff_06.0', {})
+  call term_sendkeys(buf, ":set diffopt-=context:0\<cr>")
+
   " Test 7 - 9: Test normal/patience/histogram diff algorithm
   call WriteDiffFiles(buf, ['#include <stdio.h>', '', '// Frobs foo heartily', 'int frobnitz(int foo)', '{',
       \ '    int i;', '    for(i = 0; i < 10; i++)', '    {', '        printf("Your answer is: ");',
diff --git a/src/version.c b/src/version.c
index 089c1345e..b705463e5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -780,6 +780,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    956,
+/**/
     955,
 /**/
     954,