fsck: reject misconfigured fsck.skipList

In Git, fsck operations can ignore known broken objects via the
`fsck.skipList` configuration. This option expects a path to a file with
the list of object names. When the configuration is specified without a
path, an error message is printed, but the command continues as if the
configuration was not set. Configuring `fsck.skipList` without a value
is a misconfiguration so config parsing should be more strict and reject
it.

Update `git_fsck_config()` to no longer ignore misconfiguration of
`fsck.skipList`. The same behavior is also present for
`fetch.fsck.skipList` and `receive.fsck.skipList` so the configuration
parsers for these are updated to ensure the related operations remain
consistent.

Signed-off-by: Justin Tobler <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

builtin/receive-pack.c

@@ -174,7 +174,7 @@ static int receive_pack_config(const char *var, const char *value,
 		char *path;
 
 		if (git_config_pathname(&path, var, value))
-			return 1;
+			return -1;
 		strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
 			fsck_msg_types.len ? ',' : '=', path);
 		free(path);

fetch-pack.c

@@ -1867,7 +1867,7 @@ int fetch_pack_fsck_config(const char *var, const char *value,
 		char *path ;
 
 		if (git_config_pathname(&path, var, value))
-			return 0;
+			return -1;
 		strbuf_addf(msg_types, "%cskiplist=%s",
 			msg_types->len ? ',' : '=', path);
 		free(path);

fsck.c

@@ -1353,7 +1353,7 @@ int git_fsck_config(const char *var, const char *value,
 		struct strbuf sb = STRBUF_INIT;
 
 		if (git_config_pathname(&path, var, value))
-			return 1;
+			return -1;
 		strbuf_addf(&sb, "skiplist=%s", path);
 		free(path);
 		fsck_set_msg_types(options, sb.buf);

t/t5504-fetch-receive-strict.sh

@@ -167,6 +167,8 @@ test_expect_success 'fsck with unsorted skipList' '
 
 test_expect_success 'fsck with invalid or bogus skipList input' '
 	git -c fsck.skipList=/dev/null -c fsck.missingEmail=ignore fsck &&
+	test_must_fail git -c fsck.skipList -c fsck.missingEmail=ignore fsck 2>err &&
+	test_grep "unable to parse '\'fsck.skiplist\'' from command-line config" err &&
 	test_must_fail git -c fsck.skipList=does-not-exist -c fsck.missingEmail=ignore fsck 2>err &&
 	test_grep "could not open.*: does-not-exist" err &&
 	test_must_fail git -c fsck.skipList=.git/config -c fsck.missingEmail=ignore fsck 2>err &&
@@ -213,6 +215,11 @@ test_expect_success 'fsck with exhaustive accepted skipList input (various types
 	test_must_be_empty err
 '
 
+test_expect_success 'receive-pack with missing receive.fsck.skipList path' '
+	test_must_fail git -c receive.fsck.skipList receive-pack dst 2>err &&
+	test_grep "unable to parse '\'receive.fsck.skiplist\'' from command-line config" err
+'
+
 test_expect_success 'push with receive.fsck.skipList' '
 	git push . $commit:refs/heads/bogus &&
 	rm -rf dst &&
@@ -255,6 +262,9 @@ test_expect_success 'fetch with fetch.fsck.skipList' '
 	test_must_fail git --git-dir=dst/.git fetch "file://$(pwd)" $refspec &&
 
 	# Invalid and/or bogus skipList input
+	test_must_fail git --git-dir=dst/.git -c fetch.fsck.skipList fetch \
+		"file://$(pwd)" $refspec 2>err &&
+	test_grep "unable to parse '\'fetch.fsck.skiplist\'' from command-line config" err &&
 	git --git-dir=dst/.git config fetch.fsck.skipList /dev/null &&
 	test_must_fail git --git-dir=dst/.git fetch "file://$(pwd)" $refspec &&
 	git --git-dir=dst/.git config fetch.fsck.skipList does-not-exist &&