Merge branch 'jb/diff-no-index-no-abbrev' into maint

"git diff --no-index" did not take "--no-abbrev" option.

* jb/diff-no-index-no-abbrev:
  diff: handle --no-abbrev in no-index case

diff.c

@@ -3106,7 +3106,8 @@ static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
 			abbrev = FALLBACK_DEFAULT_ABBREV;
 		if (abbrev > GIT_SHA1_HEXSZ)
 			die("BUG: oid abbreviation out of range: %d", abbrev);
-		hex[abbrev] = '\0';
+		if (abbrev)
+			hex[abbrev] = '\0';
 		return hex;
 	}
 }
@@ -3364,6 +3365,7 @@ void diff_setup(struct diff_options *options)
 
 	options->file = stdout;
 
+	options->abbrev = DEFAULT_ABBREV;
 	options->line_termination = '\n';
 	options->break_opt = -1;
 	options->rename_limit = -1;
@@ -4024,6 +4026,8 @@ int diff_opt_parse(struct diff_options *options,
 			    offending, optarg);
 		return argcount;
 	}
+	else if (!strcmp(arg, "--no-abbrev"))
+		options->abbrev = 0;
 	else if (!strcmp(arg, "--abbrev"))
 		options->abbrev = DEFAULT_ABBREV;
 	else if (skip_prefix(arg, "--abbrev=", &arg)) {

t/t4013-diff-various.sh

@@ -311,6 +311,13 @@ diff --line-prefix=abc master master^ side
 diff --dirstat master~1 master~2
 diff --dirstat initial rearrange
 diff --dirstat-by-file initial rearrange
+# No-index --abbrev and --no-abbrev
+diff --raw initial
+diff --raw --abbrev=4 initial
+diff --raw --no-abbrev initial
+diff --no-index --raw dir2 dir
+diff --no-index --raw --abbrev=4 dir2 dir
+diff --no-index --raw --no-abbrev dir2 dir
 EOF
 
 test_expect_success 'log -S requires an argument' '

t/t4013/diff.diff_--no-index_--raw_--abbrev=4_dir2_dir

+$ git diff --no-index --raw --abbrev=4 dir2 dir
+:000000 100644 0000... 0000... A	dir/sub
+$

t/t4013/diff.diff_--no-index_--raw_--no-abbrev_dir2_dir

+$ git diff --no-index --raw --no-abbrev dir2 dir
+:000000 100644 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 A	dir/sub
+$

t/t4013/diff.diff_--no-index_--raw_dir2_dir

+$ git diff --no-index --raw dir2 dir
+:000000 100644 0000000... 0000000... A	dir/sub
+$

t/t4013/diff.diff_--raw_--abbrev=4_initial

+$ git diff --raw --abbrev=4 initial
+:100644 100644 35d2... 9929... M	dir/sub
+:100644 100644 01e7... 10a8... M	file0
+:000000 100644 0000... b1e6... A	file1
+:100644 000000 01e7... 0000... D	file2
+$

t/t4013/diff.diff_--raw_--no-abbrev_initial

+$ git diff --raw --no-abbrev initial
+:100644 100644 35d242ba79ae89ac695e26b3d4c27a8e6f028f9e 992913c5aa0a5476d10c49ed0f21fc0c6d1aedf3 M	dir/sub
+:100644 100644 01e79c32a8c99c557f0757da7cb6d65b3414466d 10a8a9f3657f91a156b9f0184ed79a20adef9f7f M	file0
+:000000 100644 0000000000000000000000000000000000000000 b1e67221afe8461efd244b487afca22d46b95eb8 A	file1
+:100644 000000 01e79c32a8c99c557f0757da7cb6d65b3414466d 0000000000000000000000000000000000000000 D	file2
+$

t/t4013/diff.diff_--raw_initial

+$ git diff --raw initial
+:100644 100644 35d242b... 992913c... M	dir/sub
+:100644 100644 01e79c3... 10a8a9f... M	file0
+:000000 100644 0000000... b1e6722... A	file1
+:100644 000000 01e79c3... 0000000... D	file2
+$