Merge branch 'mh/lockfile'

The lockfile API and its users have been cleaned up.

* mh/lockfile: (38 commits)
  lockfile.h: extract new header file for the functions in lockfile.c
  hold_locked_index(): move from lockfile.c to read-cache.c
  hold_lock_file_for_append(): restore errno before returning
  get_locked_file_path(): new function
  lockfile.c: rename static functions
  lockfile: rename LOCK_NODEREF to LOCK_NO_DEREF
  commit_lock_file_to(): refactor a helper out of commit_lock_file()
  trim_last_path_component(): replace last_path_elm()
  resolve_symlink(): take a strbuf parameter
  resolve_symlink(): use a strbuf for internal scratch space
  lockfile: change lock_file::filename into a strbuf
  commit_lock_file(): use a strbuf to manage temporary space
  try_merge_strategy(): use a statically-allocated lock_file object
  try_merge_strategy(): remove redundant lock_file allocation
  struct lock_file: declare some fields volatile
  lockfile: avoid transitory invalid states
  git_config_set_multivar_in_file(): avoid call to rollback_lock_file()
  dump_marks(): remove a redundant call to rollback_lock_file()
  api-lockfile: document edge cases
  commit_lock_file(): rollback lock file on failure to rename
  ...

1 files changed, 12 insertions, 9 deletions

diff --git a/read-cache.c b/read-cache.c
index 2fc1182f22..8f3e9eb314 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -5,6 +5,7 @@
  */
 #define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
+#include "lockfile.h"
 #include "cache-tree.h"
 #include "refs.h"
 #include "dir.h"
@@ -1367,6 +1368,14 @@ static int read_index_extension(struct index_state *istate,
 	return 0;
 }
 
+int hold_locked_index(struct lock_file *lk, int die_on_error)
+{
+	return hold_lock_file_for_update(lk, get_index_file(),
+					 die_on_error
+					 ? LOCK_DIE_ON_ERROR
+					 : 0);
+}
+
 int read_index(struct index_state *istate)
 {
 	return read_index_from(istate, get_index_file());
@@ -2041,16 +2050,10 @@ void set_alternate_index_output(const char *name)
 
 static int commit_locked_index(struct lock_file *lk)
 {
-	if (alternate_index_output) {
-		if (lk->fd >= 0 && close_lock_file(lk))
-			return -1;
-		if (rename(lk->filename, alternate_index_output))
-			return -1;
-		lk->filename[0] = 0;
-		return 0;
-	} else {
+	if (alternate_index_output)
+		return commit_lock_file_to(lk, alternate_index_output);
+	else
 		return commit_lock_file(lk);
-	}
 }
 
 static int do_write_locked_index(struct index_state *istate, struct lock_file *lock,