ls-remote: pass heads/tags prefixes to transport

Unlike its arbitrary text patterns, the --heads and --tags
options to ls-remote are true prefixes. We can pass this
information to the transport code. If the v2 protocol is in
use, that will reduce the size of the ref advertisement.

Note that the test added here succeeds both before and after
the patch. This is an optimization, not a bug-fix; it's just
making sure we didn't break anything.

Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

builtin/ls-remote.c

@@ -92,6 +92,11 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 		}
 	}
 
+	if (flags & REF_TAGS)
+		argv_array_push(&ref_prefixes, "refs/tags/");
+	if (flags & REF_HEADS)
+		argv_array_push(&ref_prefixes, "refs/heads/");
+
 	remote = remote_get(dest);
 	if (!remote) {
 		if (dest)

t/t5512-ls-remote.sh

@@ -313,4 +313,13 @@ test_expect_success 'ls-remote patterns work with all protocol versions' '
 	test_cmp expect actual.v2
 '
 
+test_expect_success 'ls-remote prefixes work with all protocol versions' '
+	git for-each-ref --format="%(objectname)	%(refname)" \
+		refs/heads/ refs/tags/ >expect &&
+	git -c protocol.version=1 ls-remote --heads --tags . >actual.v1 &&
+	test_cmp expect actual.v1 &&
+	git -c protocol.version=2 ls-remote --heads --tags . >actual.v2 &&
+	test_cmp expect actual.v2
+'
+
 test_done