rebase: run post-checkout hook on checkout

The scripted version of rebase used to run this hook on the initial
checkout. The transition to built-in introduced a regression.

Signed-off-by: Orgad Shaneh <orgads@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/rebase.c

@@ -530,6 +530,7 @@ finished_rebase:
 
 #define RESET_HEAD_DETACH (1<<0)
 #define RESET_HEAD_HARD (1<<1)
+#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 
 static int reset_head(struct object_id *oid, const char *action,
 		      const char *switch_to_branch, unsigned flags,
@@ -537,6 +538,7 @@ static int reset_head(struct object_id *oid, const char *action,
 {
 	unsigned detach_head = flags & RESET_HEAD_DETACH;
 	unsigned reset_hard = flags & RESET_HEAD_HARD;
+	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 	struct object_id head_oid;
 	struct tree_desc desc[2] = { { NULL }, { NULL } };
 	struct lock_file lock = LOCK_INIT;
@@ -636,6 +638,10 @@ static int reset_head(struct object_id *oid, const char *action,
 			ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 					 UPDATE_REFS_MSG_ON_ERR);
 	}
+	if (run_hook)
+		run_hook_le(NULL, "post-checkout",
+			    oid_to_hex(orig ? orig : &null_oid),
+			    oid_to_hex(oid), "1", NULL);
 
 leave_reset_head:
 	strbuf_release(&msg);
@@ -1465,7 +1471,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 					    getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
 					    options.switch_to);
 				if (reset_head(&oid, "checkout",
-					       options.head_name, 0,
+					       options.head_name,
+					       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
 					       NULL, buf.buf) < 0) {
 					ret = !!error(_("could not switch to "
 							"%s"),
@@ -1539,7 +1546,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	strbuf_addf(&msg, "%s: checkout %s",
 		    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
 	if (reset_head(&options.onto->object.oid, "checkout", NULL,
-		       RESET_HEAD_DETACH, NULL, msg.buf))
+		       RESET_HEAD_DETACH | RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
+		       NULL, msg.buf))
 		die(_("Could not detach HEAD"));
 	strbuf_release(&msg);
 

t/t5403-post-checkout-hook.sh

@@ -13,6 +13,8 @@ test_expect_success setup '
 	EOF
 	test_commit one &&
 	test_commit two &&
+	test_commit rebase-on-me &&
+	git reset --hard HEAD^ &&
 	test_commit three
 '
 
@@ -44,6 +46,24 @@ test_expect_success 'post-checkout receives the right args when not switching br
 	test $old = $new && test $flag = 0
 '
 
+test_expect_success 'post-checkout is triggered on rebase' '
+	test_when_finished "rm -f .git/post-checkout.args" &&
+	git checkout -b rebase-test master &&
+	rm -f .git/post-checkout.args &&
+	git rebase rebase-on-me &&
+	read old new flag <.git/post-checkout.args &&
+	test $old != $new && test $flag = 1
+'
+
+test_expect_success 'post-checkout is triggered on rebase with fast-forward' '
+	test_when_finished "rm -f .git/post-checkout.args" &&
+	git checkout -b ff-rebase-test rebase-on-me^ &&
+	rm -f .git/post-checkout.args &&
+	git rebase rebase-on-me &&
+	read old new flag <.git/post-checkout.args &&
+	test $old != $new && test $flag = 1
+'
+
 test_expect_success 'post-checkout hook is triggered by clone' '
 	mkdir -p templates/hooks &&
 	write_script templates/hooks/post-checkout <<-\EOF &&