write_shared_index(): use tempfile module

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

read-cache.c

@@ -5,6 +5,7 @@
  */
 #define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "cache-tree.h"
 #include "refs.h"
@@ -2136,54 +2137,27 @@ static int write_split_index(struct index_state *istate,
 	return ret;
 }
 
-static char *temporary_sharedindex;
-
-static void remove_temporary_sharedindex(void)
-{
-	if (temporary_sharedindex) {
-		unlink_or_warn(temporary_sharedindex);
-		free(temporary_sharedindex);
-		temporary_sharedindex = NULL;
-	}
-}
-
-static void remove_temporary_sharedindex_on_signal(int signo)
-{
-	remove_temporary_sharedindex();
-	sigchain_pop(signo);
-	raise(signo);
-}
+static struct tempfile temporary_sharedindex;
 
 static int write_shared_index(struct index_state *istate,
 			      struct lock_file *lock, unsigned flags)
 {
 	struct split_index *si = istate->split_index;
-	static int installed_handler;
 	int fd, ret;
 
-	temporary_sharedindex = git_pathdup("sharedindex_XXXXXX");
-	fd = mkstemp(temporary_sharedindex);
+	fd = mks_tempfile(&temporary_sharedindex, git_path("sharedindex_XXXXXX"));
 	if (fd < 0) {
-		free(temporary_sharedindex);
-		temporary_sharedindex = NULL;
 		hashclr(si->base_sha1);
 		return do_write_locked_index(istate, lock, flags);
 	}
-	if (!installed_handler) {
-		atexit(remove_temporary_sharedindex);
-		sigchain_push_common(remove_temporary_sharedindex_on_signal);
-	}
 	move_cache_to_base_index(istate);
 	ret = do_write_index(si->base, fd, 1);
-	close(fd);
 	if (ret) {
-		remove_temporary_sharedindex();
+		delete_tempfile(&temporary_sharedindex);
 		return ret;
 	}
-	ret = rename(temporary_sharedindex,
-		     git_path("sharedindex.%s", sha1_to_hex(si->base->sha1)));
-	free(temporary_sharedindex);
-	temporary_sharedindex = NULL;
+	ret = rename_tempfile(&temporary_sharedindex,
+			      git_path("sharedindex.%s", sha1_to_hex(si->base->sha1)));
 	if (!ret)
 		hashcpy(si->base_sha1, si->base->sha1);
 	return ret;