Rev 4838: (andrew) Backport lp:bzr r5155: Reset siginterrupt flag everytime we in file:///home/pqm/archives/thelove/bzr/2.1/

[Canonical.com Patch Queue Manager]

At file:///home/pqm/archives/thelove/bzr/2.1/

------------------------------------------------------------
revno: 4838 [merge]
revision-id: pqm at pqm.ubuntu.com-20100430074110-r9ffhuboqeevhid9
parent: pqm at pqm.ubuntu.com-20100429060941-xlvrrmgolwd5gu9a
parent: andrew.bennetts at canonical.com-20100430062715-p1i2tybjsg1nehdo
committer: Canonical.com Patch Queue Manager <pqm at pqm.ubuntu.com>
branch nick: 2.1
timestamp: Fri 2010-04-30 08:41:10 +0100
message:
  (andrew) Backport lp:bzr r5155: Reset siginterrupt flag everytime we
  	handle a signal to partially workaround
  	http://bugs.python.org/issue8354.
modified:
  NEWS                           NEWS-20050323055033-4e00b5db738777ff
  bzrlib/osutils.py              osutils.py-20050309040759-eeaff12fbf77ac86
=== modified file 'NEWS'
--- a/NEWS	2010-04-29 05:14:04 +0000
+++ b/NEWS	2010-04-30 06:27:15 +0000
@@ -16,6 +16,12 @@
 * ``bzr switch`` does not die if a ConfigurableFileMerger is used.
   (Aaron Bentley, #559436)
 
+* Reset ``siginterrupt`` flag to False every time we handle a signal
+  installed with ``set_signal_handler(..., restart_syscall=True)`` (from
+  ``bzrlib.osutils``.  Reduces the likelihood of "Interrupted System Call"
+  errors after two window resizes.
+  (Andrew Bennetts)
+
 
 bzr 2.1.1
 #########

=== modified file 'bzrlib/osutils.py'
--- a/bzrlib/osutils.py	2010-03-11 00:13:08 +0000
+++ b/bzrlib/osutils.py	2010-04-30 06:27:15 +0000
@@ -1356,15 +1356,25 @@
         False)`).  May be ignored if the feature is not available on this
         platform or Python version.
     """
-    old_handler = signal.signal(signum, handler)
+    try:
+        siginterrupt = signal.siginterrupt
+    except AttributeError:
+        # siginterrupt doesn't exist on this platform, or for this version
+        # of Python.
+        siginterrupt = lambda signum, flag: None
     if restart_syscall:
-        try:
-            siginterrupt = signal.siginterrupt
-        except AttributeError: # siginterrupt doesn't exist on this platform, or for this version of
-            # Python.
-            pass
-        else:
+        def sig_handler(*args):
+            # Python resets the siginterrupt flag when a signal is
+            # received.  <http://bugs.python.org/issue8354>
+            # As a workaround for some cases, set it back the way we want it.
             siginterrupt(signum, False)
+            # Now run the handler function passed to set_signal_handler.
+            handler(*args)
+    else:
+        sig_handler = handler
+    old_handler = signal.signal(signum, sig_handler)
+    if restart_syscall:
+        siginterrupt(signum, False)
     return old_handler