Update changelog and add comment to registering of SourceFileLoader

--HG--
branch : distribute
extra : rebase_source : 2701f50b3375f9c2f2378ff22f274aade0b03107

CHANGES.txt

@@ -9,6 +9,9 @@ CHANGES
 * Fix 2 errors with Jython 2.5.
 * Fix 1 failure with Jython 2.5 and 2.7.
 * Disable workaround for Jython scripts on Linux systems.
+* Fix issue in pkg_resources where try/except around a platform-dependent
+  import would trigger hook load failures on Mercurial. See pull request 32
+  for details.
 
 ------
 0.6.32

pkg_resources.py

@@ -1325,6 +1325,9 @@ class DefaultProvider(EggProvider):
 
 register_loader_type(type(None), DefaultProvider)
 
+# Python 3.3 also supplies the SourceFileLoader.
+# Don't be tempted to do a try/except block here - it will break Mercurial
+#  hooks due to the demandimport functionality.
 if sys.version_info[:2] >= (3,3):
     import _frozen_importlib
     register_loader_type(_frozen_importlib.SourceFileLoader, DefaultProvider)