Re: [PATCH v2 0/3] pre-push hook support

[Junio C Hamano <gitster@pobox.com>]

Junio C Hamano <gitster@pobox.com> writes:

> Junio C Hamano <gitster@pobox.com> writes:
>
>> Aaron Schrab <aaron@schrab.com> writes:
>>
>>> Main changes since the initial version:
>>>
>>>  * The first patch converts the existing hook callers to use the new
>>>    find_hook() function.
>>>  * Information about what is to be pushed is now sent over a pipe rather
>>>    than passed as command-line parameters.
>>>
>>> Aaron Schrab (3):
>>>   hooks: Add function to check if a hook exists
>>>   push: Add support for pre-push hooks
>>>   Add sample pre-push hook script
>>
>> Getting much nicer.  Thanks.
>
> Hmph, t5571 seems to be flaky in that it sometimes fails but passes
> when run again.  Something timing dependent is going on???

With this patch applied, repeatedly try to

 - make sure "foreign" ref does not exist; and
 - attempt pushing the HEAD:foreign to create the "foreign" ref

until it fails, I can get it stop before the output scrolls off of
my 114 line terminal.  Then when I revert the changes to transport.[ch]
and builtin/push.c in this series, the test will keep going.

Wait.  The sample hook used in the test _is_ fed some input but it
exits without reading any.  What happens when we fork it, and it
completes execution before we even have a chance to feed a single
byte?  Wont' we get a sigpipe and die?

Yup, I think that is what is missing from run_pre_push_hook()
implementation.

diff --git a/t/t5571-pre-push-hook.sh b/t/t5571-pre-push-hook.sh
index d68fed7..050318b 100755
--- a/t/t5571-pre-push-hook.sh
+++ b/t/t5571-pre-push-hook.sh
@@ -16,8 +16,15 @@ test_expect_success 'setup' '
 	git init --bare repo1 &&
 	git remote add parent1 repo1 &&
 	test_commit one &&
-	git push parent1 HEAD:foreign
+	while :
+	do
+		git push parent1 :refs/heads/foreign &&
+		git push parent1 HEAD:foreign || break
+	done
 '
+
+exit
+
 write_script "$HOOK" <<EOF
 exit 1
 EOF