[PATCH v2] read-cache: avoid using git_path() in freshen_shared_index()

[Christian Couder <christian.couder@gmail.com>]

When performing an interactive rebase in split-index mode,
the commit message that one should rework when squashing commits
can contain some garbage instead of the usual concatenation of
both of the commit messages.

Bisecting shows that c3a0082502 (read-cache: use
freshen_shared_index() in read_index_from(), 2017-03-06) is involved,
which points to the unsafe use of git_path() in
freshen_shared_index().

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
The only changes in this v2 compared to the previous version are
in the title and commit message, which have been changed according
to:

http://public-inbox.org/git/CAP8UFD29xWU5bHwewUSq26pVTwK-gy3uSVG2aGTCrDak3620=A@mail.gmail.com/

 read-cache.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/read-cache.c b/read-cache.c
index e447751823..2f10242c24 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1682,9 +1682,10 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
  */
 static void freshen_shared_index(char *base_sha1_hex, int warn)
 {
-	const char *shared_index = git_path("sharedindex.%s", base_sha1_hex);
+	char *shared_index = git_pathdup("sharedindex.%s", base_sha1_hex);
 	if (!check_and_freshen_file(shared_index, 1) && warn)
 		warning("could not freshen shared index '%s'", shared_index);
+	free(shared_index);
 }
 
 int read_index_from(struct index_state *istate, const char *path)
-- 
2.12.0.rc0.23.g4ed838fb8d