[PATCH] test-logtoprocess: fix flaky test

[Jun Wu]

# HG changeset patch
# User Jun Wu <quark at fb.com>
# Date 1487270039 28800
#      Thu Feb 16 10:33:59 2017 -0800
# Node ID 070d9b1d8c2528e8c247b5bcaeb69aea509619a1
# Parent  6e6a461b5b60dc48a9e49cab2f3994b1345531fc
# Available At https://bitbucket.org/quark-zju/hg-draft
#              hg pull https://bitbucket.org/quark-zju/hg-draft -r 070d9b1d8c25
test-logtoprocess: fix flaky test

Commands started by logtoprocess are running asynchronously. To be able to
test the output, we need to block and wait for the output.

The patch adds "| head -n 1" to the "hg log" command so its "asynchronous"
output is waited and can be tested reliably.

diff --git a/tests/test-logtoprocess.t b/tests/test-logtoprocess.t
--- a/tests/test-logtoprocess.t
+++ b/tests/test-logtoprocess.t
@@ -67,4 +67,4 @@ Confirm that logging blocked time catche
   > EOF
 
-  $ hg log
+  $ hg log | head -n 1
   uiblocked stdio [0-9]+.[0-9]* ms command [0-9]+.[0-9]* ms (re)