pack-write.c: plug a leak in stage_tmp_packfiles()

The function `stage_tmp_packfiles()` generates a filename to use for
staging the contents of what will become the pack's ".mtimes" file.

The name is generated in `write_mtimes_file()` and the result is
returned back to `stage_tmp_packfiles()` which uses it to rename the
temporary file into place via `rename_tmp_packfiles()`.

`write_mtimes_file()` returns a `const char *`, indicating that callers
are not expected to free its result (similar to, e.g., `oid_to_hex()`).
But callers are expected to free its result, so this return type is
incorrect.

Change the function's signature to return a non-const `char *`, and free
it at the end of `stage_tmp_packfiles()`.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/pack-write.c b/pack-write.c
index f1714054951e158ca920a4a17a831914962f557e..4da0ccc5f50181d2db677394ae31ebed19ca4876 100644 (file)
--- a/pack-write.c
+++ b/pack-write.c
@@ -312,13 +312,13 @@ static void write_mtimes_trailer(struct hashfile *f, const unsigned char *hash)
        hashwrite(f, hash, the_hash_algo->rawsz);
 }
 
-static const char *write_mtimes_file(struct packing_data *to_pack,
-                                    struct pack_idx_entry **objects,
-                                    uint32_t nr_objects,
-                                    const unsigned char *hash)
+static char *write_mtimes_file(struct packing_data *to_pack,
+                              struct pack_idx_entry **objects,
+                              uint32_t nr_objects,
+                              const unsigned char *hash)
 {
        struct strbuf tmp_file = STRBUF_INIT;
-       const char *mtimes_name;
+       char *mtimes_name;
        struct hashfile *f;
        int fd;
 
@@ -544,7 +544,7 @@ void stage_tmp_packfiles(struct strbuf *name_buffer,
                         char **idx_tmp_name)
 {
        const char *rev_tmp_name = NULL;
-       const char *mtimes_tmp_name = NULL;
+       char *mtimes_tmp_name = NULL;
 
        if (adjust_shared_perm(pack_tmp_name))
                die_errno("unable to make temporary pack file readable");
@@ -568,6 +568,8 @@ void stage_tmp_packfiles(struct strbuf *name_buffer,
                rename_tmp_packfile(name_buffer, rev_tmp_name, "rev");
        if (mtimes_tmp_name)
                rename_tmp_packfile(name_buffer, mtimes_tmp_name, "mtimes");
+
+       free(mtimes_tmp_name);
 }
 
 void write_promisor_file(const char *promisor_name, struct ref **sought, int nr_sought)