[lttng-dev] [PATCH 2/5] run-report: Restore SIGPIPE default handler in subprocess calls

[Christian Babeux]

Python override the SIGPIPE default handler because it prefers to check
every write and raise an IOError exception rather than taking SIGPIPE [1].

This behavior has the unfortunate side-effect of polluting stdout with
broken pipe messages on shell pipelines invocations (e.g. echo foo |
grep something | etc.) in shell scripts spawned via subprocess.Popen().

This commit fix the polluting of stdout by restoring the default SIGPIPE
handler on subprocess calls.

[1] - http://bugs.python.org/issue1652

Signed-off-by: Christian Babeux <christian.babeux at efficios.com>
---
 tests/run-report.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/run-report.py b/tests/run-report.py
index ca6e6a3..6f559c9 100755
--- a/tests/run-report.py
+++ b/tests/run-report.py
@@ -7,7 +7,7 @@ import Queue
 import time
 import shlex
 
-from signal import signal, SIGTERM, SIGINT
+from signal import signal, SIGTERM, SIGINT, SIGPIPE, SIG_DFL
 
 SESSIOND_BIN_NAME = "lttng-sessiond"
 SESSIOND_BIN_PATH = "src/bin/lttng-sessiond/"
@@ -182,7 +182,7 @@ class TestWorker(threading.Thread):
         env = os.environ
         env['TEST_NO_SESSIOND'] = '1'
 
-        test = subprocess.Popen([bin_path_name], env=env)
+        test = subprocess.Popen([bin_path_name], env=env, preexec_fn = lambda: signal(SIGPIPE, SIG_DFL))
         test.wait()
 
         # Send ret value to main thread
-- 
1.8.0.2