use git_path_* helper functions

Long ago we added functions like git_path_merge_msg() to
replace the more dangerous git_path("MERGE_MSG"). Over time
some new calls to the latter have crept it. Let's convert
them to use the safer form.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: peff

builtin/commit.c

@@ -821,9 +821,9 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 					"If this is not correct, please remove the file\n"
 					"	%s\n"
 					"and try again.\n"),
-				git_path(whence == FROM_MERGE
-					 ? "MERGE_HEAD"
-					 : "CHERRY_PICK_HEAD"));
+				whence == FROM_MERGE ?
+					git_path_merge_head() :
+					git_path_cherry_pick_head());
 		}
 
 		fprintf(s->fp, "\n");

builtin/pull.c

@@ -332,7 +332,7 @@ static int git_pull_config(const char *var, const char *value, void *cb)
  */
 static void get_merge_heads(struct sha1_array *merge_heads)
 {
-	const char *filename = git_path("FETCH_HEAD");
+	const char *filename = git_path_fetch_head();
 	FILE *fp;
 	struct strbuf sb = STRBUF_INIT;
 	unsigned char sha1[GIT_SHA1_RAWSZ];
@@ -791,7 +791,7 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	if (read_cache_unmerged())
 		die_resolve_conflict("pull");
 
-	if (file_exists(git_path("MERGE_HEAD")))
+	if (file_exists(git_path_merge_head()))
 		die_conclude_merge();
 
 	if (get_sha1("HEAD", orig_head))

sequencer.c

@@ -1057,12 +1057,12 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 			cleanup_commit_message = 1;
 			msg_file = rebase_path_fixup_msg();
 		} else {
-			const char *dest = git_path("SQUASH_MSG");
+			const char *dest = git_path_squash_msg();
 			unlink(dest);
 			if (copy_file(dest, rebase_path_squash_msg(), 0666))
 				return error(_("could not rename '%s' to '%s'"),
 					     rebase_path_squash_msg(), dest);
-			unlink(git_path("MERGE_MSG"));
+			unlink(git_path_merge_msg());
 			msg_file = dest;
 			edit = 1;
 		}
@@ -1812,10 +1812,10 @@ static int error_failed_squash(struct commit *commit,
 		return error(_("could not rename '%s' to '%s'"),
 			rebase_path_squash_msg(), rebase_path_message());
 	unlink(rebase_path_fixup_msg());
-	unlink(git_path("MERGE_MSG"));
-	if (copy_file(git_path("MERGE_MSG"), rebase_path_message(), 0666))
+	unlink(git_path_merge_msg());
+	if (copy_file(git_path_merge_msg(), rebase_path_message(), 0666))
 		return error(_("could not copy '%s' to '%s'"),
-			     rebase_path_message(), git_path("MERGE_MSG"));
+			     rebase_path_message(), git_path_merge_msg());
 	return error_with_patch(commit, subject, subject_len, opts, 1, 0);
 }
 
@@ -2158,7 +2158,7 @@ static int commit_staged_changes(struct replay_opts *opts)
 	if (has_unstaged_changes(1))
 		return error(_("cannot rebase: You have unstaged changes."));
 	if (!has_uncommitted_changes(0)) {
-		const char *cherry_pick_head = git_path("CHERRY_PICK_HEAD");
+		const char *cherry_pick_head = git_path_cherry_pick_head();
 
 		if (file_exists(cherry_pick_head) && unlink(cherry_pick_head))
 			return error(_("could not remove CHERRY_PICK_HEAD"));