am: allow passing --no-verify flag

The git-am --no-verify flag is analogous to the same flag passed to
git-commit. It bypasses the pre-applypatch and applypatch-msg hooks
if they are enabled.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-am.txt

@@ -9,7 +9,7 @@ git-am - Apply a series of patches from a mailbox
 SYNOPSIS
 --------
 [verse]
-'git am' [--signoff] [--keep] [--[no-]keep-cr] [--[no-]utf8]
+'git am' [--signoff] [--keep] [--[no-]keep-cr] [--[no-]utf8] [--no-verify]
 	 [--[no-]3way] [--interactive] [--committer-date-is-author-date]
 	 [--ignore-date] [--ignore-space-change | --ignore-whitespace]
 	 [--whitespace=<option>] [-C<n>] [-p<n>] [--directory=<dir>]
@@ -138,6 +138,12 @@ include::rerere-options.txt[]
 --interactive::
 	Run interactively.
 
+-n::
+--no-verify::
+	By default, the pre-applypatch and applypatch-msg hooks are run.
+	When any of `--no-verify` or `-n` is given, these are bypassed.
+	See also linkgit:githooks[5].
+
 --committer-date-is-author-date::
 	By default the command records the date from the e-mail
 	message as the commit author date, and uses the time of

builtin/am.c

@@ -117,6 +117,7 @@ struct am_state {
 
 	/* various operating modes and command line options */
 	int interactive;
+	int no_verify;
 	int threeway;
 	int quiet;
 	int signoff; /* enum signoff_type */
@@ -472,10 +473,12 @@ static void am_destroy(const struct am_state *state)
  */
 static int run_applypatch_msg_hook(struct am_state *state)
 {
-	int ret;
+	int ret = 0;
 
 	assert(state->msg);
-	ret = run_hooks_l("applypatch-msg", am_path(state, "final-commit"), NULL);
+
+	if (!state->no_verify)
+		ret = run_hooks_l("applypatch-msg", am_path(state, "final-commit"), NULL);
 
 	if (!ret) {
 		FREE_AND_NULL(state->msg);
@@ -1640,7 +1643,7 @@ static void do_commit(const struct am_state *state)
 	const char *reflog_msg, *author, *committer = NULL;
 	struct strbuf sb = STRBUF_INIT;
 
-	if (run_hooks("pre-applypatch"))
+	if (!state->no_verify && run_hooks("pre-applypatch"))
 		exit(1);
 
 	if (write_cache_as_tree(&tree, 0, NULL))
@@ -2329,6 +2332,8 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 	struct option options[] = {
 		OPT_BOOL('i', "interactive", &state.interactive,
 			N_("run interactively")),
+		OPT_BOOL('n', "no-verify", &state.no_verify,
+			N_("bypass pre-applypatch and applypatch-msg hooks")),
 		OPT_HIDDEN_BOOL('b', "binary", &binary,
 			N_("historical option -- no-op")),
 		OPT_BOOL('3', "3way", &state.threeway,

t/t4150-am.sh

@@ -345,6 +345,21 @@ test_expect_success 'am with failing applypatch-msg hook' '
 	test_cmp_rev first HEAD
 '
 
+test_expect_success 'am with failing applypatch-msg hook (no verify)' '
+	rm -fr .git/rebase-apply &&
+	git reset --hard &&
+	git checkout first &&
+	test_hook applypatch-msg <<-\EOF &&
+	echo hook-message >"$1"
+	exit 1
+	EOF
+	git am --no-verify patch1 &&
+	test_path_is_missing .git/rebase-apply &&
+	git diff --exit-code second &&
+	git log -1 --format=format:%B >actual &&
+	test_cmp msg actual
+'
+
 test_expect_success 'am with pre-applypatch hook' '
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
@@ -374,6 +389,23 @@ test_expect_success 'am with failing pre-applypatch hook' '
 	test_cmp_rev first HEAD
 '
 
+test_expect_success 'am with failing pre-applypatch hook (no verify)' '
+	rm -fr .git/rebase-apply &&
+	git reset --hard &&
+	git checkout first &&
+	touch empty-file &&
+	test_hook pre-applypatch <<-\EOF &&
+	rm empty-file
+	exit 1
+	EOF
+	git am --no-verify patch1 &&
+	test_path_is_missing .git/rebase-apply &&
+	test_path_is_file empty-file &&
+	git diff --exit-code second &&
+	git log -1 --format=format:%B >actual &&
+	test_cmp msg actual
+'
+
 test_expect_success 'am with post-applypatch hook' '
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&