[PATCH] pack-refs: dereference .git/packed-refs if it is a symlink

[Peter Baumann <waste.manager@gmx.de>]

git-new-workdir creates a new working directory where everything
necessary, including .git/packed-refs, is symlinked to your master repo.
But git-pack-refs breaks the symlink, so you could accidentally loose some
refs. This fixes it to first dereference .git/packed-refs if it is a
symlink.

Signed-off-by: Peter Baumann <waste.manager@gmx.de>
---
 builtin-pack-refs.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/builtin-pack-refs.c b/builtin-pack-refs.c
index d080e30..afa9b5a 100644
--- a/builtin-pack-refs.c
+++ b/builtin-pack-refs.c
@@ -89,6 +89,8 @@ int cmd_pack_refs(int argc, const char **argv, const char *prefix)
 {
 	int fd, i;
 	struct pack_refs_cb_data cbdata;
+	struct stat st;
+	char *ref_file_name;
 
 	memset(&cbdata, 0, sizeof(cbdata));
 
@@ -113,7 +115,18 @@ int cmd_pack_refs(int argc, const char **argv, const char *prefix)
 	if (i != argc)
 		usage(builtin_pack_refs_usage);
 
-	fd = hold_lock_file_for_update(&packed, git_path("packed-refs"), 1);
+	ref_file_name = git_path("packed-refs");
+	if (!lstat(ref_file_name, &st) && S_ISLNK(st.st_mode)) {
+		char *buf = xmalloc(st.st_size + 1);
+		if (readlink(ref_file_name, buf, st.st_size + 1) != st.st_size) {
+			free(buf);
+			die("readlink failed\n");
+		}
+		buf[st.st_size] = '\0';
+		ref_file_name = buf;
+	}
+
+	fd = hold_lock_file_for_update(&packed, ref_file_name, 1);
 	cbdata.refs_file = fdopen(fd, "w");
 	if (!cbdata.refs_file)
 		die("unable to create ref-pack file structure (%s)",
-- 
1.5.1