Rev 5321: The symbol_versioning module can now cleanup after itself - in http://bazaar.launchpad.net/~lifeless/bzr/globalzapping

[Robert Collins]

At http://bazaar.launchpad.net/~lifeless/bzr/globalzapping

------------------------------------------------------------
revno: 5321
revision-id: robertc at robertcollins.net-20100625061121-0cx949gxhae5aeib
parent: pqm at pqm.ubuntu.com-20100625042410-r2zawge1wxx9ma9p
committer: Robert Collins <robertc at robertcollins.net>
branch nick: globalzapping
timestamp: Fri 2010-06-25 16:11:21 +1000
message:
  The symbol_versioning module can now cleanup after itself -
  ``suppress_deprecation_warnings`` now returns a cleanup function.
  (Robert Collins)
=== modified file 'NEWS'
--- a/NEWS	2010-06-25 04:24:10 +0000
+++ b/NEWS	2010-06-25 06:11:21 +0000
@@ -179,6 +179,10 @@
 
 * Improved ``bzrlib.urlutils`` to handle lp:foo/bar URLs. (Gordon Tyler)
 
+* The symbol_versioning module can now cleanup after itself -
+  ``suppress_deprecation_warnings`` now returns a cleanup function.
+  (Robert Collins)
+
 Testing
 *******
 

=== modified file 'bzrlib/symbol_versioning.py'
--- a/bzrlib/symbol_versioning.py	2009-09-15 02:28:34 +0000
+++ b/bzrlib/symbol_versioning.py	2010-06-25 06:11:21 +0000
@@ -314,6 +314,7 @@
 
     :param override: If True, always set the ignore, if False, only set the
         ignore if there isn't already a filter.
+    :return: A callable to remove the new warnings this added.
     """
     import warnings
     if not override and _check_for_filter(error_only=False):
@@ -321,6 +322,10 @@
         # then skip it.
         return
     warnings.filterwarnings('ignore', category=DeprecationWarning)
+    filter = warnings.filters[0]
+    def cleanup():
+        warnings.filters.remove(filter)
+    return cleanup
 
 
 def activate_deprecation_warnings(override=True):

=== modified file 'bzrlib/tests/test_symbol_versioning.py'
--- a/bzrlib/tests/test_symbol_versioning.py	2010-04-23 08:51:52 +0000
+++ b/bzrlib/tests/test_symbol_versioning.py	2010-06-25 06:11:21 +0000
@@ -241,6 +241,11 @@
         symbol_versioning.suppress_deprecation_warnings()
         self.assertFirstWarning('ignore', DeprecationWarning)
 
+    def test_set_restore_filters(self):
+        original_filters = warnings.filters[:]
+        symbol_versioning.suppress_deprecation_warnings()()
+        self.assertEqual(original_filters, warnings.filters)
+
     def test_suppress_deprecation_with_warning_filter(self):
         """don't suppress if we already have a filter"""
         warnings.filterwarnings('error', category=Warning)