upload-pack.c: fix filter spec quoting bug

Fix a bug in upload-pack.c that occurs when you combine partial
clone and uploadpack.packObjectsHook. You can reproduce it as
follows:

    git clone -u 'git -c uploadpack.allowfilter '\
	'-c uploadpack.packobjectshook=env '\
	'upload-pack' --filter=blob:none --no-local \
	src.git dst.git

Be careful with the line endings because this has a long quoted
string as the -u argument.

The error I get when I run this is:

	Cloning into '/tmp/broken'...
	remote: fatal: invalid filter-spec ''blob:none''
	error: git upload-pack: git-pack-objects died with error.
	fatal: git upload-pack: aborting due to possible repository corruption on the remote side.
	remote: aborting due to possible repository corruption on the remote side.
	fatal: early EOF
	fatal: index-pack failed

The problem is caused by unneeded quoting.

This bug was already present in 10ac85c (upload-pack: add object
filtering for partial clone, 2017-12-08) when the server side filter
support was introduced.  In fact, in 10ac85c this was broken
regardless of uploadpack.packObjectsHook. Then in 0b6069f
(fetch-pack: test support excluding large blobs, 2017-12-08) the
quoting was removed but only behind a conditional that depends on
whether uploadpack.packObjectsHook is set.

Because uploadpack.packObjectsHook is apparently rarely used, nobody
noticed the problematic quoting could still happen.

Remove the conditional quoting and add a test for partial clone in
t5544-pack-objects-hook.

Signed-off-by: Jacob Vosmaer <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jacobvosmaer

t/t5544-pack-objects-hook.sh

@@ -59,4 +59,13 @@ test_expect_success 'hook does not run from repo config' '
 	test_path_is_missing .git/hook.stdout
 '
 
+test_expect_success 'hook works with partial clone' '
+	clear_hook_results &&
+	test_config_global uploadpack.packObjectsHook ./hook &&
+	test_config_global uploadpack.allowFilter true &&
+	git clone --bare --no-local --filter=blob:none . dst.git &&
+	git -C dst.git rev-list --objects --missing=print HEAD >objects &&
+	grep "^?" objects
+'
+
 test_done

upload-pack.c

@@ -305,14 +305,7 @@ static void create_pack_file(struct upload_pack_data *pack_data,
 	if (pack_data->filter_options.choice) {
 		const char *spec =
 			expand_list_objects_filter_spec(&pack_data->filter_options);
-		if (pack_objects.use_shell) {
-			struct strbuf buf = STRBUF_INIT;
-			sq_quote_buf(&buf, spec);
-			strvec_pushf(&pack_objects.args, "--filter=%s", buf.buf);
-			strbuf_release(&buf);
-		} else {
-			strvec_pushf(&pack_objects.args, "--filter=%s", spec);
-		}
+		strvec_pushf(&pack_objects.args, "--filter=%s", spec);
 	}
 	if (uri_protocols) {
 		for (i = 0; i < uri_protocols->nr; i++)