help: fix leaking struct cmdnames

We're populating multiple `struct cmdnames`, but don't ever free them.
Create a common exit path where we do so.

Note that this also requires us to use `FREE_AND_NULL()` when freeing
`cmdnames::names`, as we may otherwise try to free it multiple times.

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

Author: pks-t

help.c

@@ -169,7 +169,7 @@ void cmdnames_release(struct cmdnames *cmds)
 	int i;
 	for (i = 0; i < cmds->cnt; ++i)
 		free(cmds->names[i]);
-	free(cmds->names);
+	FREE_AND_NULL(cmds->names);
 	cmds->cnt = 0;
 	cmds->alloc = 0;
 }
@@ -619,6 +619,7 @@ const char *help_unknown_cmd(const char *cmd)
 	struct cmdnames main_cmds = { 0 };
 	struct cmdnames other_cmds = { 0 };
 	struct cmdname_help *common_cmds;
+	const char *assumed = NULL;
 
 	read_early_config(the_repository, git_unknown_cmd_config, &cfg);
 
@@ -630,7 +631,7 @@ const char *help_unknown_cmd(const char *cmd)
 
 	if (cfg.autocorrect == AUTOCORRECT_NEVER) {
 		fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
-		exit(1);
+		goto out;
 	}
 
 	load_command_list("git-", &main_cmds, &other_cmds);
@@ -695,7 +696,7 @@ const char *help_unknown_cmd(const char *cmd)
 			; /* still counting */
 	}
 	if (cfg.autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
-		const char *assumed = main_cmds.names[0]->name;
+		assumed = main_cmds.names[0]->name;
 		main_cmds.names[0] = NULL;
 		cmdnames_release(&main_cmds);
 		fprintf_ln(stderr,
@@ -714,16 +715,19 @@ const char *help_unknown_cmd(const char *cmd)
 			answer = git_prompt(msg.buf, PROMPT_ECHO);
 			strbuf_release(&msg);
 			if (!(starts_with(answer, "y") ||
-			      starts_with(answer, "Y")))
-				exit(1);
+			      starts_with(answer, "Y"))) {
+				assumed = NULL;
+				goto out;
+			}
 		} else {
 			fprintf_ln(stderr,
 				   _("Continuing in %0.1f seconds, "
 				     "assuming that you meant '%s'."),
 				   (float)cfg.autocorrect/10.0, assumed);
 			sleep_millisec(cfg.autocorrect * 100);
 		}
-		return assumed;
+
+		goto out;
 	}
 
 	fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
@@ -738,7 +742,13 @@ const char *help_unknown_cmd(const char *cmd)
 			fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 	}
 
-	exit(1);
+out:
+	cmdnames_release(&cfg.aliases);
+	cmdnames_release(&main_cmds);
+	cmdnames_release(&other_cmds);
+	if (!assumed)
+		exit(1);
+	return assumed;
 }
 
 void get_version_info(struct strbuf *buf, int show_build_options)