+"""subprocess management for dak
+
+@copyright: 2013, Ansgar Burchardt <ansgar@debian.org>
+@license: GPL-2+
+"""
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+import signal
+import subprocess
+
+#
+def fix_signal_handlers():
+ """reset signal handlers to default action.
+
+ Python changes the signal handler to SIG_IGN for a few signals which
+ causes unexpected behaviour in child processes. This function resets
+ them to their default action.
+
+ Reference: http://bugs.python.org/issue1652
+ """
+ for signal_name in ('SIGPIPE', 'SIGXFZ', 'SIGXFSZ'):
+ try:
+ signal_number = getattr(signal, signal_name)
+ signal.signal(signal_number, signal.SIG_DFL)
+ except AttributeError:
+ pass
+
+def _generate_preexec_fn(other_preexec_fn=None):
+ def preexec_fn():
+ fix_signal_handlers()
+ if other_preexec_fn is not None:
+ other_preexec_fn()
+ return preexec_fn
+
+def call(*args, **kwargs):
+ """wrapper around subprocess.call that fixes signal handling"""
+ preexec_fn = _generate_preexec_fn(kwargs.get('preexec_fn'))
+ kwargs['preexec_fn'] = preexec_fn
+ return subprocess.call(*args, **kwargs)
+
+def check_call(*args, **kwargs):
+ """wrapper around subprocess.check_call that fixes signal handling"""
+ preexec_fn = _generate_preexec_fn(kwargs.get('preexec_fn'))
+ kwargs['preexec_fn'] = preexec_fn
+ return subprocess.check_call(*args, **kwargs)
+
+def check_output(*args, **kwargs):
+ """wrapper around subprocess.check_output that fixes signal handling"""
+ preexec_fn = _generate_preexec_fn(kwargs.get('preexec_fn'))
+ kwargs['preexec_fn'] = preexec_fn
+ return subprocess.check_output(*args, **kwargs)
+
+def Popen(*args, **kwargs):
+ """wrapper around subprocess.Popen that fixes signal handling"""
+ preexec_fn = _generate_preexec_fn(kwargs.get('preexec_fn'))
+ kwargs['preexec_fn'] = preexec_fn
+ return subprocess.Popen(*args, **kwargs)