Re: [PATCH] t5570: forward git-daemon messages in a different way

From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Apr 16, 2012, 15:43 UTC
Message-ID: <4F8C3E0F.2040300@in.waw.pl>
In-Reply-To: <20120414122127.GA31220@ecki>

On 04/14/2012 02:21 PM, Clemens Buchacher wrote:

Show 21 quoted lines

> On Sat, Apr 14, 2012 at 02:13:58PM +0200, Clemens Buchacher wrote:
>>
>> In order to better understand the problem on your side, can you execute
>> this script and tell me what it does for you?
> 
> Oops, this is what I really wanted:
> 
> #!/bin/sh
> 
> mkfifo fd
> yes>fd&
> pid=$!
> {
> 	read line
> 	echo $line
> 	cat<fd&
> }<fd
> sleep 1
> kill $pid
> wait $pid
> rm -f fd

Hi, many thanks for looking into this. I'm sorry I didn't reply sooner, but I was away for the weekend.

> And as a consequence, t5570 tests fail for you? I cannot reproduce with
> bash 4.2.24(2). Which git version are you seeing this with?

Yes. Example test output is:

----(on master 146fe8ce2)------------------------------------------------------------------ $ (cd t && GIT_TEST_GIT_DAEMON=t ./t5570*sh) ok 1 - setup repository ok 2 - create git-accessible bare repository not ok - 3 clone git repository # # git clone "$GIT_DAEMON_URL/repo.git" clone && # test_cmp file clone/file # not ok - 4 fetch changes via git protocol # # echo content >>file && # git commit -a -m two && # git push public && # (cd clone && git pull) && # test_cmp file clone/file # not ok 5 - remote detects correct HEAD # TODO known breakage ok 6 - prepare pack objects ok 7 - fetch notices corrupt pack ok 8 - fetch notices corrupt idx not ok - 9 clone non-existent # test_remote_error clone nowhere.git 'access denied or repository not exported' not ok - 10 push disabled # test_remote_error push repo.git 'access denied or repository not exported' not ok - 11 read access denied # test_remote_error -x fetch repo.git 'access denied or repository not exported' not ok - 12 not exported # test_remote_error -n fetch repo.git 'access denied or repository not exported' ./t5570-git-daemon.sh: 59: kill: No such process

error: git daemon exited with status: 141 -----------------------------------------------------------------------------------------

OK, I run your test scripts and found the problem (test.sh is the first version, and test2.sh is the second version with 'cat' inside {}). Yikes! I have /bin/sh symlinked to dash, and dash behaves differently:

% bash -x test2.sh | wc -l
+ mkfifo fd
+ pid=10685
+ yes
+ read line
+ echo y
+ sleep 1
+ cat
+ kill 10685
+ wait 10685
test2.sh: line 13: 10685 Terminated              yes > fd
+ rm -f fd
45400064

% dash -x test2.sh | wc -l
+ mkfifo fd
+ pid=10738
+ read line
+ yes
+ echo y
+ sleep 1
+ kill 10738
test2.sh: 12: kill: No such process

+ wait 10738
+ rm -f fd
^C

It hangs at the end until killed with ^C. This seem to happen fairly reliably (nineteen times out of twenty or so). This is with dash 0.5.7-3 and 0.5.5.1-7.4 from debian. With bash test2.sh seems to always run successfully.

I also run test.sh for comparison, and dash runs test.sh successfully every once in a while, and test.sh always fails with bash.

So my patch was totally bogus, it was just probably changing the timing.

Now your patches (on top of next): 'git-daemon wrapper to wait until daemon is ready' fixes the problem, thanks!

(I now see that they are both in pu: pu runs fine too.)

Thanks, Zbyszek