[Python-checkins] r71881 - in python/branches/py3k: Lib/test/support.py Misc/NEWS

Sat Apr 25 14:48:44 CEST 2009

Author: walter.doerwald
Date: Sat Apr 25 14:48:43 2009
New Revision: 71881
Log:
Merged revisions 71875 via svnmerge from 
svn+ssh://pythondev@svn.python.org/python/trunk
........
 r71875 | walter.doerwald | 2009年04月25日 14:15:07 +0200 (Sa, 25 Apr 2009) | 7 lines
 
 Issue #5837: Certain sequences of calls to set() and unset() for
 support.EnvironmentVarGuard objects restored the environment variables
 incorrectly on __exit__.
 
 Fix this by recording the initial value of each environment variable on the
 first access in set() or unset().
........
Modified:
 python/branches/py3k/ (props changed)
 python/branches/py3k/Lib/test/support.py
 python/branches/py3k/Misc/NEWS
Modified: python/branches/py3k/Lib/test/support.py
==============================================================================

--- python/branches/py3k/Lib/test/support.py	(original)
+++ python/branches/py3k/Lib/test/support.py	Sat Apr 25 14:48:43 2009
@@ -516,30 +516,31 @@
 a context manager."""
 
 def __init__(self):
- self._environ = os.environ
- self._unset = set()
- self._reset = dict()
+ self._changed = {}
 
 def set(self, envvar, value):
- if envvar not in self._environ:
- self._unset.add(envvar)
- else:
- self._reset[envvar] = self._environ[envvar]
- self._environ[envvar] = value
+ # Remember the initial value on the first access
+ if envvar not in self._changed:
+ self._changed[envvar] = os.environ.get(envvar)
+ os.environ[envvar] = value
 
 def unset(self, envvar):
- if envvar in self._environ:
- self._reset[envvar] = self._environ[envvar]
- del self._environ[envvar]
+ # Remember the initial value on the first access
+ if envvar not in self._changed:
+ self._changed[envvar] = os.environ.get(envvar)
+ if envvar in os.environ:
+ del os.environ[envvar]
 
 def __enter__(self):
 return self
 
 def __exit__(self, *ignore_exc):
- for envvar, value in self._reset.items():
- self._environ[envvar] = value
- for unset in self._unset:
- del self._environ[unset]
+ for (k, v) in self._changed.items():
+ if v is None:
+ if k in os.environ:
+ del os.environ[k]
+ else:
+ os.environ[k] = v
 
 class TransientResource(object):
 
Modified: python/branches/py3k/Misc/NEWS
==============================================================================
--- python/branches/py3k/Misc/NEWS	(original)
+++ python/branches/py3k/Misc/NEWS	Sat Apr 25 14:48:43 2009
@@ -124,6 +124,10 @@
 other modules with both C and Python implementations in the stdlib
 can be adjusted to use it over time.
 
+- Issue #5837: Certain sequences of calls to set() and unset() for
+ support.EnvironmentVarGuard objects restored the environment variables
+ incorrectly on __exit__.
+
 
 What's New in Python 3.1 alpha 2?
 =================================
