[PATCH 2/3] read-cache.c: move tempfile creation/cleanup out of write_shared_index

[Nguyễn Thái Ngọc Duy]

For one thing, we have more consistent cleanup procedure now and always
keep errno intact.

The real purpose is the ability to break out of write_locked_index()
early when mks_tempfile() fails in the next patch. It's more awkward to
do it if this mks_tempfile() is still inside write_shared_index().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
Signed-off-by: Junio C Hamano <gits...@pobox.com>
---
 read-cache.c | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/read-cache.c b/read-cache.c
index 536086e1fe..c568643f55 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -2472,31 +2472,18 @@ static int clean_shared_index_files(const char 
*current_hex)
 }
 
 static int write_shared_index(struct index_state *istate,
-                             struct lock_file *lock, unsigned flags)
+                             struct tempfile **temp)
 {
-       struct tempfile *real_temp;
-       struct tempfile **temp = &real_temp;
        struct split_index *si = istate->split_index;
        int ret;
 
-       real_temp = mks_tempfile(git_path("sharedindex_XXXXXX"));
-       if (!real_temp) {
-               hashclr(si->base_sha1);
-               return do_write_locked_index(istate, lock, flags);
-       }
-       temp = &real_temp;
        move_cache_to_base_index(istate);
        ret = do_write_index(si->base, *temp, 1);
-       if (ret) {
-               delete_tempfile(temp);
+       if (ret)
                return ret;
-       }
        ret = adjust_shared_perm(get_tempfile_path(*temp));
        if (ret) {
-               int save_errno = errno;
                error("cannot fix permission bits on %s", 
get_tempfile_path(*temp));
-               delete_tempfile(temp);
-               errno = save_errno;
                return ret;
        }
        ret = rename_tempfile(temp,
@@ -2567,7 +2554,21 @@ int write_locked_index(struct index_state *istate, 
struct lock_file *lock,
        new_shared_index = istate->cache_changed & SPLIT_INDEX_ORDERED;
 
        if (new_shared_index) {
-               ret = write_shared_index(istate, lock, flags);
+               struct tempfile *temp;
+               int saved_errno;
+
+               temp = mks_tempfile(git_path("sharedindex_XXXXXX"));
+               if (!temp) {
+                       hashclr(si->base_sha1);
+                       ret = do_write_locked_index(istate, lock, flags);
+               } else
+                       ret = write_shared_index(istate, &temp);
+
+               saved_errno = errno;
+               if (is_tempfile_active(temp))
+                       delete_tempfile(&temp);
+               errno = saved_errno;
+
                if (ret)
                        goto out;
        }
-- 
2.16.0.47.g3d9b0fac3a