[PATCH] builtin-rm: fix index lock file path

[Olivier Marin <dkr+ml.git@free.fr>]

From: Olivier Marin <dkr@freesurf.fr>

When hold_locked_index() is called with a relative git_dir and you are
outside the work tree, the lock file become relative to the current
directory. So when later setup_work_tree() change the current directory
it breaks lock file path and commit_locked_index() fails.

This patch move index locking code after setup_work_tree() call to make
lock file relative to the working tree as it should be and add a test
case.

Noticed by Nick Andrew.

Signed-off-by: Olivier Marin <dkr@freesurf.fr>
---
 builtin-rm.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/builtin-rm.c b/builtin-rm.c
index 56454ec..ee8247b 100644
--- a/builtin-rm.c
+++ b/builtin-rm.c
@@ -146,11 +146,6 @@ int cmd_rm(int argc, const char **argv, const char *prefix)
 
 	git_config(git_default_config, NULL);
 
-	newfd = hold_locked_index(&lock_file, 1);
-
-	if (read_cache() < 0)
-		die("index file corrupt");
-
 	argc = parse_options(argc, argv, builtin_rm_options, builtin_rm_usage, 0);
 	if (!argc)
 		usage_with_options(builtin_rm_usage, builtin_rm_options);
@@ -158,6 +153,11 @@ int cmd_rm(int argc, const char **argv, const char *prefix)
 	if (!index_only)
 		setup_work_tree();
 
+	newfd = hold_locked_index(&lock_file, 1);
+
+	if (read_cache() < 0)
+		die("index file corrupt");
+
 	pathspec = get_pathspec(prefix, argv);
 	seen = NULL;
 	for (i = 0; pathspec[i] ; i++)
-- 
1.5.6.3.440.g489d7