Merge lp:~fullermd/brz/silence-git-apply-test into lp:brz

[Matthew Fuller]

Silence output from patch(1) in git-apply test.

[Jelmer Vernooij (jelmer)]

I think we'd actually want to fix this further upstream and just pass stdout=self.outf in cmd_git_apply_patch.run().

That way, we don't have to muck about with dup2, which will inevitably break on Windows.

review: Needs Fixing

[Jelmer Vernooij (jelmer)]

Proposed an alternative here that should work on Windows https://code.launchpad.net/~jelmer/brz/patch-silent/+merge/365620

[Jelmer Vernooij (jelmer)]

Marking this as rejected since we've landed an alternative fix that will also work on Windows.

[Jelmer Vernooij (jelmer)]

Thanks for reporting the bug and the original MP!

Unmerged revisions

7296. By Matthew Fuller on 2019-03-24

Silence output from patch(1) in git-apply test.

The test suite stubs in stdout/err wrappers for the python code, but
doesn't mess with the underlying file descriptors, so spawned off
processes still get the terminal. cmd_git_apply._apply_patch() uses
subprocess to spawn off the system patch(1) to do the application, and
patch talks a lot about what it's doing. While patch has a -s arg to
quiet it down, we probably want it speaking a lot in normal use so the
user can see what's going on, so just switch stdout to /dev/null
around the run_bzr call in the test instead.

An argument could be made that the test suite as a whole should be
better about moving the fd's so subprocesses can't hit the terminal
directly, but for the moment, this seems to be the only test where it
matters.

=== modified file 'breezy/git/tests/test_blackbox.py'
--- breezy/git/tests/test_blackbox.py	2019-02-17 04:08:56 +0000
+++ breezy/git/tests/test_blackbox.py	2019-03-24 21:04:11 +0000
@@ -493,7 +493,21 @@
 +Certainty: certain
 +Fixed-Lintian-Tags: out-of-date-standards-version
 """)
+
+        # git-apply shells out to patch(1) with subprocess, which
+        # splatters the screen.  Fake up stdout so the subprocess's
+        # output is silenced.
+        import sys, os
+        stdout_fd = sys.stdout.fileno()
+        saved_stdout = os.dup(stdout_fd)
+        devnull = os.open(os.devnull, os.O_WRONLY)
+
+        sys.stdout.flush()
+        os.dup2(devnull, stdout_fd)
         output, error = self.run_bzr('git-apply foo.patch')
+        sys.stdout.flush()
+        os.dup2(saved_stdout, stdout_fd)
+
         self.assertContainsRe(
             error,
             'Committing to: .*\n'