Re: [PATCH v3 3/4] fetch-pack: split out fsck config parsing

[Patrick Steinhardt <ps@pks.im>]

On Thu, Nov 28, 2024 at 12:25:44PM +0900, Junio C Hamano wrote:
> Justin Tobler <jltobler@gmail.com> writes:
> 
> > For `fetch_pack_fsck_config()` to discern between errors and unhandled
> > config variables, the return code when `git_config_path()` errors is
> > changed to a different value also indicating success. This frees up the
> > previous return code to now indicate the provided config variable
> > was unhandled. The behavior remains functionally the same.
> 
> > @@ -1866,9 +1866,9 @@ static int fetch_pack_config_cb(const char *var, const char *value,
> >  		char *path ;
> >  
> >  		if (git_config_pathname(&path, var, value))
> > -			return 1;
> > +			return 0;
> 
> So, after getting complaint about a misconfiguration, the caller
> used to be able to, if they wanted to, tell two cases apart: a
> misconfigured variable was ignored here, and we happily parsed the
> configuration.  Now they no longer can tell them apart, because we
> return 0 for both cases.

I wonder why we want to ignore these errors though. Grepping through the
codebase surfaces that all other callsites of `git_config_pathname()`
return its return value directly, which means that we'll die in case the
path name cannot be parsed. Shouldn't we do the same here, or is there a
good reason why we need to ignore it other than "We used to do it like
that"? In other words, I would have the below diff.

Other than that this patch series looks good to me.

Patrick

diff --git a/fetch-pack.c b/fetch-pack.c
index fe1fb3c1b7c..c60627bba4e 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1863,10 +1863,13 @@ static int fetch_pack_config_cb(const char *var, const char *value,
 	const char *msg_id;
 
 	if (strcmp(var, "fetch.fsck.skiplist") == 0) {
-		char *path ;
+		char *path;
+		int err;
+
+		err = git_config_pathname(&path, var, value);
+		if (err < 0)
+			return -1;
 
-		if (git_config_pathname(&path, var, value))
-			return 1;
 		strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
 			fsck_msg_types.len ? ',' : '=', path);
 		free(path);
diff --git a/t/t5504-fetch-receive-strict.sh b/t/t5504-fetch-receive-strict.sh
index 138e6778a47..73d6b3874de 100755
--- a/t/t5504-fetch-receive-strict.sh
+++ b/t/t5504-fetch-receive-strict.sh
@@ -240,6 +240,15 @@ test_expect_success 'push with receive.fsck.skipList' '
 	git push --porcelain dst bogus
 '
 
+test_expect_success 'fetch with implitcit fetch.fsck.skipList value fails' '
+	test_when_finished "rm -rf source repo" &&
+	git init source &&
+	test_commit -C source initial &&
+	git init repo &&
+	test_must_fail git -C repo -c fetch.fsck.skipList fetch "file://$(pwd)/source" 2>err &&
+	test_grep "unable to parse ${SQ}fetch.fsck.skiplist${SQ}" err
+'
+
 test_expect_success 'fetch with fetch.fsck.skipList' '
 	refspec=refs/heads/bogus:refs/heads/bogus &&
 	git push . $commit:refs/heads/bogus &&