Rev 2501: Add convenience utf8 decode routine for handling strings that might be None in http://bazaar.launchpad.net/~bzr/bzr/dirstate

[Robert Collins]

At http://bazaar.launchpad.net/~bzr/bzr/dirstate

------------------------------------------------------------
revno: 2501
revision-id: robertc at robertcollins.net-20070304221043-gxthr6yo2w4yy6mx
parent: mbp at sourcefrog.net-20070304080909-xjsidexprse2bar5
committer: Robert Collins <robertc at robertcollins.net>
branch nick: dirstate
timestamp: Mon 2007-03-05 09:10:43 +1100
message:
  Add convenience utf8 decode routine for handling strings that might be None
modified:
  bzrlib/cache_utf8.py           cache_utf8.py-20060810004311-x4cph46la06h9azm-1
  bzrlib/tests/test_cache_utf8.py test_cache_utf8.py-20060810004311-x4cph46la06h9azm-2
=== modified file 'bzrlib/cache_utf8.py'
--- a/bzrlib/cache_utf8.py	2007-02-10 02:48:43 +0000
+++ b/bzrlib/cache_utf8.py	2007-03-04 22:10:43 +0000
@@ -24,6 +24,12 @@
 
 _utf8_encode = codecs.getencoder("utf-8")
 _utf8_decode = codecs.getdecoder("utf-8")
+# wrap _utf8_decode to support None->None for optional strings.
+def _utf8_decode_with_None(bytestring, _utf8_decode=_utf8_decode):
+    if bytestring is None:
+        return (None, 0)
+    else:
+        return _utf8_decode(bytestring)
 
 # Map revisions from and to utf8 encoding
 # Whenever we do an encode/decode operation, we save the result, so that

=== modified file 'bzrlib/tests/test_cache_utf8.py'
--- a/bzrlib/tests/test_cache_utf8.py	2007-02-09 16:41:00 +0000
+++ b/bzrlib/tests/test_cache_utf8.py	2007-03-04 22:10:43 +0000
@@ -109,3 +109,6 @@
 
         utf8_x = cache_utf8.encode(uni_x)
         self.assertIs(utf8_x, x)
+
+    def test_decode_with_None(self):
+        self.assertEqual((None, 0), cache_utf8._utf8_decode_with_None(None))