[PATCH 1/1] blame: skip missing ignore-revs-file's

[Noah Pendleton <noah.pendleton@gmail.com>]

Setting the config option `blame.ignoreRevsFile` globally to eg
`.git-blame-ignore-revs` causes `git blame` to error when the file
doesn't exist in the current repository:

```
fatal: could not open object name list: .git-blame-ignore-revs
```

Instead, just skip over ignore-rev files that don't exist.

Signed-off-by: Noah Pendleton <noah.pendleton@gmail.com>
---
 Documentation/blame-options.txt |  2 +-
 Documentation/config/blame.txt  |  3 ++-
 builtin/blame.c                 |  2 +-
 t/t8013-blame-ignore-revs.sh    | 10 ++++++----
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/Documentation/blame-options.txt b/Documentation/blame-options.txt
index 117f4cf806..2a8f54cc9c 100644
--- a/Documentation/blame-options.txt
+++ b/Documentation/blame-options.txt
@@ -134,7 +134,7 @@ take effect.
 	`fsck.skipList`.  This option may be repeated, and these files will be
 	processed after any files specified with the `blame.ignoreRevsFile` config
 	option.  An empty file name, `""`, will clear the list of revs from
-	previously processed files.
+	previously processed files. Any files that do not exist will be skipped.
 
 -h::
 	Show help message.
diff --git a/Documentation/config/blame.txt b/Documentation/config/blame.txt
index 4d047c1790..f7f49a4ac2 100644
--- a/Documentation/config/blame.txt
+++ b/Documentation/config/blame.txt
@@ -25,7 +25,8 @@ blame.ignoreRevsFile::
 	line, in linkgit:git-blame[1].  Whitespace and comments beginning with
 	`#` are ignored.  This option may be repeated multiple times.  Empty
 	file names will reset the list of ignored revisions.  This option will
-	be handled before the command line option `--ignore-revs-file`.
+	be handled before the command line option `--ignore-revs-file`. If the
+	specified file does not exist it will be skipped.
 
 blame.markUnblamableLines::
 	Mark lines that were changed by an ignored revision that we could not
diff --git a/builtin/blame.c b/builtin/blame.c
index 641523ff9a..e5b45eddf4 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -835,7 +835,7 @@ static void build_ignorelist(struct blame_scoreboard *sb,
 	for_each_string_list_item(i, ignore_revs_file_list) {
 		if (!strcmp(i->string, ""))
 			oidset_clear(&sb->ignore_list);
-		else
+		else if (file_exists(i->string))
 			oidset_parse_file_carefully(&sb->ignore_list, i->string,
 						    peel_to_commit_oid, sb);
 	}
diff --git a/t/t8013-blame-ignore-revs.sh b/t/t8013-blame-ignore-revs.sh
index b18633dee1..56956adb14 100755
--- a/t/t8013-blame-ignore-revs.sh
+++ b/t/t8013-blame-ignore-revs.sh
@@ -127,18 +127,20 @@ test_expect_success override_ignore_revs_file '
 	grep -E "^[0-9a-f]+ [0-9]+ 2" blame_raw | sed -e "s/ .*//" >actual &&
 	test_cmp expect actual
 	'
-test_expect_success bad_files_and_revs '
+test_expect_success bad_revs '
 	test_must_fail git blame file --ignore-rev NOREV 2>err &&
 	test_i18ngrep "cannot find revision NOREV to ignore" err &&
 
-	test_must_fail git blame file --ignore-revs-file NOFILE 2>err &&
-	test_i18ngrep "could not open.*: NOFILE" err &&
-
 	echo NOREV >ignore_norev &&
 	test_must_fail git blame file --ignore-revs-file ignore_norev 2>err &&
 	test_i18ngrep "invalid object name: NOREV" err
 '
 
+# Non-existent ignore-revs-file should be ignored.
+test_expect_success bad_file '
+	git blame file --ignore-revs-file NOFILE
+'
+
 # For ignored revs that have added 'unblamable' lines, mark those lines with a
 # '*'
 # 	A--B--X--Y
-- 
2.32.0