Cleaning up http_proxy on http tests

[Gustavo Niemeyer]

The attached patch will cleanup the http_proxy environment
variable during the setup of the local HTTP server for local
tests. Currently, it may show errors like the one below due
to the proxy.

----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/niemeyer/src/bzr.mergelog2/bzrlib/selftest/testfetch.py", line 138, in test_weaves_are_retrieved_once
    len([log for log in self.weblogs if log.endswith(weave_suffix)]))
AssertionError: 1 != 0

-- 
Gustavo Niemeyer
http://niemeyer.net
-------------- next part --------------
=== modified file 'bzrlib/selftest/HTTPTestUtil.py'
--- bzrlib/selftest/HTTPTestUtil.py
+++ bzrlib/selftest/HTTPTestUtil.py
@@ -137,9 +137,15 @@
         self._http_thread = threading.Thread(target=self._http_start)
         self._http_thread.setDaemon(True)
         self._http_thread.start()
+        self._http_proxy = os.environ.get("http_proxy")
+        if self._http_proxy is not None:
+            del os.environ["http_proxy"]
 
     def tearDown(self):
         self._http_running = False
         self._http_thread.join()
+        if self._http_proxy is not None:
+            import os
+            os.environ["http_proxy"] = self._http_proxy
         TestCaseInTempDir.tearDown(self)