builtin/format-patch: fix various trivial memory leaks

There are various memory leaks hit by git-format-patch(1). Basically all
of them are trivial, except that un-setting `diffopt.no_free` requires
us to unset the `diffopt.file` because we manually close it already.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

builtin/log.c

@@ -1827,12 +1827,14 @@ static struct commit *get_base_commit(const struct format_config *cfg,
 				if (die_on_failure) {
 					die(_("failed to find exact merge base"));
 				} else {
+					free_commit_list(merge_base);
 					free(rev);
 					return NULL;
 				}
 			}
 
 			rev[i] = merge_base->item;
+			free_commit_list(merge_base);
 		}
 
 		if (rev_nr % 2)
@@ -2023,6 +2025,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	const char *rfc = NULL;
 	int creation_factor = -1;
 	const char *signature = git_version_string;
+	char *signature_to_free = NULL;
 	char *signature_file_arg = NULL;
 	struct keep_callback_data keep_callback_data = {
 		.cfg = &cfg,
@@ -2443,7 +2446,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 
 		if (strbuf_read_file(&buf, signature_file, 128) < 0)
 			die_errno(_("unable to read signature file '%s'"), signature_file);
-		signature = strbuf_detach(&buf, NULL);
+		signature = signature_to_free = strbuf_detach(&buf, NULL);
 	} else if (cfg.signature) {
 		signature = cfg.signature;
 	}
@@ -2548,12 +2551,13 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			else
 				print_signature(signature, rev.diffopt.file);
 		}
-		if (output_directory)
+		if (output_directory) {
 			fclose(rev.diffopt.file);
+			rev.diffopt.file = NULL;
+		}
 	}
 	stop_progress(&progress);
 	free(list);
-	free(branch_name);
 	if (ignore_if_in_upstream)
 		free_patch_ids(&ids);
 
@@ -2565,11 +2569,14 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	strbuf_release(&rdiff_title);
 	free(description_file);
 	free(signature_file_arg);
+	free(signature_to_free);
+	free(branch_name);
 	free(to_free);
 	free(rev.message_id);
 	if (rev.ref_message_ids)
 		string_list_clear(rev.ref_message_ids, 0);
 	free(rev.ref_message_ids);
+	rev.diffopt.no_free = 0;
 	release_revisions(&rev);
 	format_config_release(&cfg);
 	return 0;

t/t4014-format-patch.sh

@@ -8,6 +8,7 @@ test_description='various format-patch tests'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-terminal.sh