git branch -D: give a better error message when lockfile creation fails

Previously the old error message just told the user that it was not
possible to delete the ref from the packed-refs file. Give instructions
on how to resolve the problem.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index 1a6412d..a5eeead 100644
--- a/cache.h
+++ b/cache.h
@@ -489,6 +489,7 @@ struct lock_file {
 };
 #define LOCK_DIE_ON_ERROR 1
 #define LOCK_NODEREF 2
+extern int unable_to_lock_error(const char *path, int err);
 extern NORETURN void unable_to_lock_index_die(const char *path, int err);
 extern int hold_lock_file_for_update(struct lock_file *, const char *path, int);
 extern int hold_lock_file_for_append(struct lock_file *, const char *path, int);