Merge branch 'ab/plug-leak-in-revisions'

Plug the memory leaks from the trickiest API of all, the revision
walker.

* ab/plug-leak-in-revisions: (27 commits)
  revisions API: add a TODO for diff_free(&revs->diffopt)
  revisions API: have release_revisions() release "topo_walk_info"
  revisions API: have release_revisions() release "date_mode"
  revisions API: call diff_free(&revs->pruning) in revisions_release()
  revisions API: release "reflog_info" in release revisions()
  revisions API: clear "boundary_commits" in release_revisions()
  revisions API: have release_revisions() release "prune_data"
  revisions API: have release_revisions() release "grep_filter"
  revisions API: have release_revisions() release "filter"
  revisions API: have release_revisions() release "cmdline"
  revisions API: have release_revisions() release "mailmap"
  revisions API: have release_revisions() release "commits"
  revisions API users: use release_revisions() for "prune_data" users
  revisions API users: use release_revisions() with UNLEAK()
  revisions API users: use release_revisions() in builtin/log.c
  revisions API users: use release_revisions() in http-push.c
  revisions API users: add "goto cleanup" for release_revisions()
  stash: always have the owner of "stash_info" free it
  revisions API users: use release_revisions() needing REV_INFO_INIT
  revision.[ch]: document and move code declared around "init"
  ...

1 files changed, 62 insertions, 53 deletions

diff --git a/builtin/stash.c b/builtin/stash.c
index 3fe549f7d3..68b28f2375 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -117,6 +117,10 @@ struct stash_info {
 	int has_u;
 };
 
+#define STASH_INFO_INIT { \
+	.revision = STRBUF_INIT, \
+}
+
 static void free_stash_info(struct stash_info *info)
 {
 	strbuf_release(&info->revision);
@@ -158,10 +162,8 @@ static int get_stash_info(struct stash_info *info, int argc, const char **argv)
 	if (argc == 1)
 		commit = argv[0];
 
-	strbuf_init(&info->revision, 0);
 	if (!commit) {
 		if (!ref_exists(ref_stash)) {
-			free_stash_info(info);
 			fprintf_ln(stderr, _("No stash entries found."));
 			return -1;
 		}
@@ -175,11 +177,8 @@ static int get_stash_info(struct stash_info *info, int argc, const char **argv)
 
 	revision = info->revision.buf;
 
-	if (get_oid(revision, &info->w_commit)) {
-		error(_("%s is not a valid reference"), revision);
-		free_stash_info(info);
-		return -1;
-	}
+	if (get_oid(revision, &info->w_commit))
+		return error(_("%s is not a valid reference"), revision);
 
 	assert_stash_like(info, revision);
 
@@ -198,7 +197,7 @@ static int get_stash_info(struct stash_info *info, int argc, const char **argv)
 		info->is_stash_ref = !strcmp(expanded_ref, ref_stash);
 		break;
 	default: /* Invalid or ambiguous */
-		free_stash_info(info);
+		break;
 	}
 
 	free(expanded_ref);
@@ -616,10 +615,10 @@ restore_untracked:
 
 static int apply_stash(int argc, const char **argv, const char *prefix)
 {
-	int ret;
+	int ret = -1;
 	int quiet = 0;
 	int index = 0;
-	struct stash_info info;
+	struct stash_info info = STASH_INFO_INIT;
 	struct option options[] = {
 		OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 		OPT_BOOL(0, "index", &index,
@@ -631,9 +630,10 @@ static int apply_stash(int argc, const char **argv, const char *prefix)
 			     git_stash_apply_usage, 0);
 
 	if (get_stash_info(&info, argc, argv))
-		return -1;
+		goto cleanup;
 
 	ret = do_apply_stash(prefix, &info, index, quiet);
+cleanup:
 	free_stash_info(&info);
 	return ret;
 }
@@ -669,20 +669,25 @@ static int do_drop_stash(struct stash_info *info, int quiet)
 	return 0;
 }
 
-static void assert_stash_ref(struct stash_info *info)
+static int get_stash_info_assert(struct stash_info *info, int argc,
+				 const char **argv)
 {
-	if (!info->is_stash_ref) {
-		error(_("'%s' is not a stash reference"), info->revision.buf);
-		free_stash_info(info);
-		exit(1);
-	}
+	int ret = get_stash_info(info, argc, argv);
+
+	if (ret < 0)
+		return ret;
+
+	if (!info->is_stash_ref)
+		return error(_("'%s' is not a stash reference"), info->revision.buf);
+
+	return 0;
 }
 
 static int drop_stash(int argc, const char **argv, const char *prefix)
 {
-	int ret;
+	int ret = -1;
 	int quiet = 0;
-	struct stash_info info;
+	struct stash_info info = STASH_INFO_INIT;
 	struct option options[] = {
 		OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 		OPT_END()
@@ -691,22 +696,21 @@ static int drop_stash(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, options,
 			     git_stash_drop_usage, 0);
 
-	if (get_stash_info(&info, argc, argv))
-		return -1;
-
-	assert_stash_ref(&info);
+	if (get_stash_info_assert(&info, argc, argv))
+		goto cleanup;
 
 	ret = do_drop_stash(&info, quiet);
+cleanup:
 	free_stash_info(&info);
 	return ret;
 }
 
 static int pop_stash(int argc, const char **argv, const char *prefix)
 {
-	int ret;
+	int ret = -1;
 	int index = 0;
 	int quiet = 0;
-	struct stash_info info;
+	struct stash_info info = STASH_INFO_INIT;
 	struct option options[] = {
 		OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 		OPT_BOOL(0, "index", &index,
@@ -717,25 +721,25 @@ static int pop_stash(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, options,
 			     git_stash_pop_usage, 0);
 
-	if (get_stash_info(&info, argc, argv))
-		return -1;
+	if (get_stash_info_assert(&info, argc, argv))
+		goto cleanup;
 
-	assert_stash_ref(&info);
 	if ((ret = do_apply_stash(prefix, &info, index, quiet)))
 		printf_ln(_("The stash entry is kept in case "
 			    "you need it again."));
 	else
 		ret = do_drop_stash(&info, quiet);
 
+cleanup:
 	free_stash_info(&info);
 	return ret;
 }
 
 static int branch_stash(int argc, const char **argv, const char *prefix)
 {
-	int ret;
+	int ret = -1;
 	const char *branch = NULL;
-	struct stash_info info;
+	struct stash_info info = STASH_INFO_INIT;
 	struct child_process cp = CHILD_PROCESS_INIT;
 	struct option options[] = {
 		OPT_END()
@@ -752,7 +756,7 @@ static int branch_stash(int argc, const char **argv, const char *prefix)
 	branch = argv[0];
 
 	if (get_stash_info(&info, argc - 1, argv + 1))
-		return -1;
+		goto cleanup;
 
 	cp.git_cmd = 1;
 	strvec_pushl(&cp.args, "checkout", "-b", NULL);
@@ -764,8 +768,8 @@ static int branch_stash(int argc, const char **argv, const char *prefix)
 	if (!ret && info.is_stash_ref)
 		ret = do_drop_stash(&info, 0);
 
+cleanup:
 	free_stash_info(&info);
-
 	return ret;
 }
 
@@ -843,8 +847,8 @@ static void diff_include_untracked(const struct stash_info *info, struct diff_op
 static int show_stash(int argc, const char **argv, const char *prefix)
 {
 	int i;
-	int ret = 0;
-	struct stash_info info;
+	int ret = -1;
+	struct stash_info info = STASH_INFO_INIT;
 	struct rev_info rev;
 	struct strvec stash_args = STRVEC_INIT;
 	struct strvec revision_args = STRVEC_INIT;
@@ -862,6 +866,7 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 			      UNTRACKED_ONLY, PARSE_OPT_NONEG),
 		OPT_END()
 	};
+	int do_usage = 0;
 
 	init_diff_ui_defaults();
 	git_config(git_diff_ui_config, NULL);
@@ -879,10 +884,8 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 			strvec_push(&revision_args, argv[i]);
 	}
 
-	ret = get_stash_info(&info, stash_args.nr, stash_args.v);
-	strvec_clear(&stash_args);
-	if (ret)
-		return -1;
+	if (get_stash_info(&info, stash_args.nr, stash_args.v))
+		goto cleanup;
 
 	/*
 	 * The config settings are applied only if there are not passed
@@ -896,16 +899,14 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 			rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
 
 		if (!show_stat && !show_patch) {
-			free_stash_info(&info);
-			return 0;
+			ret = 0;
+			goto cleanup;
 		}
 	}
 
 	argc = setup_revisions(revision_args.nr, revision_args.v, &rev, NULL);
-	if (argc > 1) {
-		free_stash_info(&info);
-		usage_with_options(git_stash_show_usage, options);
-	}
+	if (argc > 1)
+		goto usage;
 	if (!rev.diffopt.output_format) {
 		rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 		diff_setup_done(&rev.diffopt);
@@ -930,8 +931,17 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	}
 	log_tree_diff_flush(&rev);
 
+	ret = diff_result_code(&rev.diffopt, 0);
+cleanup:
+	strvec_clear(&stash_args);
 	free_stash_info(&info);
-	return diff_result_code(&rev.diffopt, 0);
+	release_revisions(&rev);
+	if (do_usage)
+		usage_with_options(git_stash_show_usage, options);
+	return ret;
+usage:
+	do_usage = 1;
+	goto cleanup;
 }
 
 static int do_store_stash(const struct object_id *w_commit, const char *stash_msg,
@@ -1065,7 +1075,6 @@ static int check_changes_tracked_files(const struct pathspec *ps)
 		goto done;
 	}
 
-	object_array_clear(&rev.pending);
 	result = run_diff_files(&rev, 0);
 	if (diff_result_code(&rev.diffopt, result)) {
 		ret = 1;
@@ -1073,7 +1082,7 @@ static int check_changes_tracked_files(const struct pathspec *ps)
 	}
 
 done:
-	clear_pathspec(&rev.prune_data);
+	release_revisions(&rev);
 	return ret;
 }
 
@@ -1284,9 +1293,7 @@ static int stash_working_tree(struct stash_info *info, const struct pathspec *ps
 
 done:
 	discard_index(&istate);
-	UNLEAK(rev);
-	object_array_clear(&rev.pending);
-	clear_pathspec(&rev.prune_data);
+	release_revisions(&rev);
 	strbuf_release(&diff_output);
 	remove_path(stash_index_path.buf);
 	return ret;
@@ -1428,9 +1435,9 @@ done:
 
 static int create_stash(int argc, const char **argv, const char *prefix)
 {
-	int ret = 0;
+	int ret;
 	struct strbuf stash_msg_buf = STRBUF_INIT;
-	struct stash_info info;
+	struct stash_info info = STASH_INFO_INIT;
 	struct pathspec ps;
 
 	/* Starting with argv[1], since argv[0] is "create" */
@@ -1445,6 +1452,7 @@ static int create_stash(int argc, const char **argv, const char *prefix)
 	if (!ret)
 		printf_ln("%s", oid_to_hex(&info.w_commit));
 
+	free_stash_info(&info);
 	strbuf_release(&stash_msg_buf);
 	return ret;
 }
@@ -1453,7 +1461,7 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 			 int keep_index, int patch_mode, int include_untracked, int only_staged)
 {
 	int ret = 0;
-	struct stash_info info;
+	struct stash_info info = STASH_INFO_INIT;
 	struct strbuf patch = STRBUF_INIT;
 	struct strbuf stash_msg_buf = STRBUF_INIT;
 	struct strbuf untracked_files = STRBUF_INIT;
@@ -1652,6 +1660,7 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 	}
 
 done:
+	free_stash_info(&info);
 	strbuf_release(&stash_msg_buf);
 	return ret;
 }