Patch 1012740:  cStringIO's truncate doesn't

truncate() left the stream position unchanged, which meant the
"truncated" data didn't go away:

>>> io.write('abc')
>>> io.truncate(0)
>>> io.write('xyz')
>>> io.getvalue()
'abcxyz'

Patch by Dima Dorfman.
diff --git a/Misc/NEWS b/Misc/NEWS
index a8aee9c..6b1dcff 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -41,6 +41,11 @@
 Extension modules
 -----------------
 
+- Patch 1012740:  truncate() on a writeable cStringIO now resets the
+  position to the end of the stream.  This is consistent with the original
+  StringIO module and avoids inadvertently resurrecting data that was
+  supposed to have been truncated away.
+
 - Added socket.socketpair().
 
 Library
@@ -59,7 +64,7 @@
 - A new function tkFont.nametofont was added to return an existing
   font. The Font class constructor now has an additional exists argument
   which, if True, requests to return/configure an existing font, rather
-  than creating a new one. 
+  than creating a new one.
 
 - Updated the decimal package's min() and max() methods to match the
   latest revision of the General Decimal Arithmetic Specification.