hook: reject unknown hook names in git-hook(1)

Teach "git hook run" and "git hook list" to reject hook event names
that are not recognized by Git. This helps catch typos such as
"prereceive" when "pre-receive" was intended, since in 99% of the
cases users want known (already-existing) hook names.

The list of known hooks is derived from the generated hook-list.h
(built from Documentation/githooks.adoc). This is why the Makefile
is updated, so builtin/hook.c depends on hook-list.h. In meson the
header is already a dependency for all builtins, no change required.

The "--allow-unknown-hook-name" flag can be used to bypass this check.

Suggested-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 33 insertions, 2 deletions

diff --git a/builtin/hook.c b/builtin/hook.c
index f671e7f91a..c0585587e5 100644
--- a/builtin/hook.c
+++ b/builtin/hook.c
@@ -4,12 +4,22 @@
 #include "environment.h"
 #include "gettext.h"
 #include "hook.h"
+#include "hook-list.h"
 #include "parse-options.h"
 
 #define BUILTIN_HOOK_RUN_USAGE \
-	N_("git hook run [--ignore-missing] [--to-stdin=<path>] <hook-name> [-- <hook-args>]")
+	N_("git hook run [--allow-unknown-hook-name] [--ignore-missing] [--to-stdin=<path>] <hook-name> [-- <hook-args>]")
 #define BUILTIN_HOOK_LIST_USAGE \
-	N_("git hook list [-z] [--show-scope] <hook-name>")
+	N_("git hook list [--allow-unknown-hook-name] [-z] [--show-scope] <hook-name>")
+
+static int is_known_hook(const char *name)
+{
+	const char **p;
+	for (p = hook_name_list; *p; p++)
+		if (!strcmp(*p, name))
+			return 1;
+	return 0;
+}
 
 static const char * const builtin_hook_usage[] = {
 	BUILTIN_HOOK_RUN_USAGE,
@@ -34,6 +44,7 @@ static int list(int argc, const char **argv, const char *prefix,
 	const char *hookname = NULL;
 	int line_terminator = '\n';
 	int show_scope = 0;
+	int allow_unknown = 0;
 	int ret = 0;
 
 	struct option list_options[] = {
@@ -41,6 +52,8 @@ static int list(int argc, const char **argv, const char *prefix,
 			    N_("use NUL as line terminator"), '\0'),
 		OPT_BOOL(0, "show-scope", &show_scope,
 			 N_("show the config scope that defined each hook")),
+		OPT_BOOL(0, "allow-unknown-hook-name", &allow_unknown,
+			 N_("allow running a hook with a non-native hook name")),
 		OPT_END(),
 	};
 
@@ -57,6 +70,13 @@ static int list(int argc, const char **argv, const char *prefix,
 
 	hookname = argv[0];
 
+	if (!allow_unknown && !is_known_hook(hookname)) {
+		error(_("unknown hook event '%s';\n"
+			"use --allow-unknown-hook-name to allow non-native hook names"),
+		      hookname);
+		return 1;
+	}
+
 	head = list_hooks(repo, hookname, NULL);
 
 	if (!head->nr) {
@@ -103,8 +123,11 @@ static int run(int argc, const char **argv, const char *prefix,
 	int i;
 	struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
 	int ignore_missing = 0;
+	int allow_unknown = 0;
 	const char *hook_name;
 	struct option run_options[] = {
+		OPT_BOOL(0, "allow-unknown-hook-name", &allow_unknown,
+			 N_("allow running a hook with a non-native hook name")),
 		OPT_BOOL(0, "ignore-missing", &ignore_missing,
 			 N_("silently ignore missing requested <hook-name>")),
 		OPT_STRING(0, "to-stdin", &opt.path_to_stdin, N_("path"),
@@ -136,6 +159,14 @@ static int run(int argc, const char **argv, const char *prefix,
 	repo_config(the_repository, git_default_config, NULL);
 
 	hook_name = argv[0];
+
+	if (!allow_unknown && !is_known_hook(hook_name)) {
+		error(_("unknown hook event '%s';\n"
+			"use --allow-unknown-hook-name to allow non-native hook names"),
+		      hook_name);
+		return 1;
+	}
+
 	if (!ignore_missing)
 		opt.error_if_missing = 1;
 	ret = run_hooks_opt(the_repository, hook_name, &opt);