Hi Gábor,

On Tue, 7 Jan 2020, SZEDER Gábor wrote:

On Wed, Dec 25, 2019 at 11:56:52AM +0000, Johannes Schindelin via GitGitGadget wrote:

quoted

The Perl version supports post-processing the colored diff (that is
generated in addition to the uncolored diff, intended to offer a
prettier user experience) by a command configured via that config
setting, and now the built-in version does that, too.

So this patch makes the test 'detect bogus diffFilter output' in
't3701-add-interactive.sh' succeed with the builtin interactive add,
but I stumbled upon a test failure caused by SIGPIPE in an
experimental Travis CI s390x build:

  expecting success of 3701.49 'detect bogus diffFilter output':
          git reset --hard &&

          echo content >test &&
          test_config interactive.diffFilter "echo too-short" &&
          printf y >y &&
          test_must_fail force_color git add -p <y

  + git reset --hard
  HEAD is now at 6ee5ee5 test
  + echo content
  + test_config interactive.diffFilter echo too-short
  + printf y
  + test_must_fail force_color git add -p
  test_must_fail: died by signal 13: force_color git add -p
  error: last command exited with $?=1

Turns out it's a general issue, and

  GIT_TEST_ADD_I_USE_BUILTIN=1 ./t3701-add-interactive.sh -r 39,49 --stress

fails within 10 seconds on my Linux box, whereas the scripted 'add -p'
managed to survive a couple hundred repetitions.

You're right, of course. And I had let that slip for too long, as I saw it
sporadically happen in the Azure Pipeline, too.

This took quite a while to figure out, and I won't claim that I understand
_all_ the details: I _think_ that `stdin` being so short "breaks the pipe"
and interferes with `add -p`'s normal operation, so I needed to explicitly
use the `sigchain` feature to ignore `SIGPIPE` during `add -p`'s main
loop.

Thanks,
Dscho