repack: refactor finding pack prefix

Create a new find_pack_prefix() to refactor code that handles finding
the pack prefix from the packtmp and packdir global variables, as we are
going to need this feature again in following commit.

Signed-off-by: Christian Couder <[email protected]
Signed-off-by: Junio C Hamano <[email protected]>

Author: chriscool

builtin/repack.c

@@ -893,6 +893,17 @@ static int write_cruft_pack(const struct pack_objects_args *args,
 	return finish_pack_objects_cmd(&cmd, names, local);
 }
 
+static const char *find_pack_prefix(const char *packdir, const char *packtmp)
+{
+	const char *pack_prefix;
+	if (!skip_prefix(packtmp, packdir, &pack_prefix))
+		die(_("pack prefix %s does not begin with objdir %s"),
+		    packtmp, packdir);
+	if (*pack_prefix == '/')
+		pack_prefix++;
+	return pack_prefix;
+}
+
 int cmd_repack(int argc, const char **argv, const char *prefix)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;
@@ -1139,12 +1150,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		printf_ln(_("Nothing new to pack."));
 
 	if (pack_everything & PACK_CRUFT) {
-		const char *pack_prefix;
-		if (!skip_prefix(packtmp, packdir, &pack_prefix))
-			die(_("pack prefix %s does not begin with objdir %s"),
-			    packtmp, packdir);
-		if (*pack_prefix == '/')
-			pack_prefix++;
+		const char *pack_prefix = find_pack_prefix(packdir, packtmp);
 
 		if (!cruft_po_args.window)
 			cruft_po_args.window = po_args.window;