--- a/0.9.x/ChangeLog
+++ b/0.9.x/ChangeLog
@@ -3,7 +3,11 @@
 (?, from branches/stable/0.9.x)
 
  * Fixed catalogs' charset values not being recognized (ticket #66).
-	
+ * Fixed fuzzy matching when updating message catalogs (ticket #82).
+ * Fixed bug in catalog updating, that in some cases pulled in
+   translations from different catalogs based on the same template.
+
+
 Version 0.9.1
 http://svn.edgewall.org/repos/babel/tags/0.9.1/
 (Sep 7 2007, from branches/stable/0.9.x)

--- a/0.9.x/babel/messages/catalog.py
+++ b/0.9.x/babel/messages/catalog.py
@@ -92,6 +92,11 @@
                 return cmp(self.id, obj.id[0])
         return cmp(self.id, obj.id)
 
+    def clone(self):
+        return Message(self.id, self.string, self.locations, self.flags,
+                       self.auto_comments, self.user_comments,
+                       self.previous_id, self.lineno)
+
     def fuzzy(self):
         return 'fuzzy' in self.flags
     fuzzy = property(fuzzy, doc="""\
@@ -231,11 +236,11 @@
 
     >>> catalog = Catalog(project='Foobar', version='1.0',
     ...                   copyright_holder='Foo Company')
-    >>> print catalog.header_comment
+    >>> print catalog.header_comment #doctest: +ELLIPSIS
     # Translations template for Foobar.
-    # Copyright (C) 2007 Foo Company
+    # Copyright (C) ... Foo Company
     # This file is distributed under the same license as the Foobar project.
-    # FIRST AUTHOR <EMAIL@ADDRESS>, 2007.
+    # FIRST AUTHOR <EMAIL@ADDRESS>, ....
     #
 
     The header can also be set from a string. Any known upper-case variables
@@ -611,17 +616,31 @@
         :param no_fuzzy_matching: whether to use fuzzy matching of message IDs
         """
         messages = self._messages
+        remaining = messages.copy()
         self._messages = odict()
 
+        # Prepare for fuzzy matching
+        fuzzy_candidates = []
+        if not no_fuzzy_matching:
+            fuzzy_candidates = [
+                self._key_for(msgid) for msgid in messages
+                if msgid and messages[msgid].string
+            ]
+        fuzzy_matches = set()
+
         def _merge(message, oldkey, newkey):
+            message = message.clone()
             fuzzy = False
-            oldmsg = messages.pop(oldkey)
             if oldkey != newkey:
                 fuzzy = True
+                fuzzy_matches.add(oldkey)
+                oldmsg = messages.get(oldkey)
                 if isinstance(oldmsg.id, basestring):
                     message.previous_id = [oldmsg.id]
                 else:
                     message.previous_id = list(oldmsg.id)
+            else:
+                oldmsg = remaining.pop(oldkey)
             message.string = oldmsg.string
             if isinstance(message.id, (list, tuple)):
                 if not isinstance(message.string, (list, tuple)):
@@ -649,14 +668,17 @@
                     if no_fuzzy_matching is False:
                         # do some fuzzy matching with difflib
                         matches = get_close_matches(key.lower().strip(),
-                            [self._key_for(msgid) for msgid in messages], 1)
+                                                    fuzzy_candidates, 1)
                         if matches:
                             _merge(message, matches[0], key)
                             continue
 
                     self[message.id] = message
 
-        self.obsolete = messages
+        self.obsolete = odict()
+        for msgid in remaining:
+            if no_fuzzy_matching or msgid not in fuzzy_matches:
+                self.obsolete[msgid] = remaining[msgid]
 
     def _key_for(self, id):
         """The key for a message is just the singular ID even for pluralizable

--- a/0.9.x/babel/messages/tests/catalog.py
+++ b/0.9.x/babel/messages/tests/catalog.py
@@ -131,6 +131,40 @@
         self.assertEqual('Voh', cat['foo'].string)
         self.assertEqual(True, cat['foo'].fuzzy)
 
+    def test_update_fuzzy_matching_no_msgstr(self):
+        cat = catalog.Catalog()
+        cat.add('fo', '')
+        tmpl = catalog.Catalog()
+        tmpl.add('fo')
+        tmpl.add('foo')
+        cat.update(tmpl)
+        assert 'fo' in cat
+        assert 'foo' in cat
+
+        self.assertEqual('', cat['fo'].string)
+        self.assertEqual(False, cat['fo'].fuzzy)
+        self.assertEqual(None, cat['foo'].string)
+        self.assertEqual(False, cat['foo'].fuzzy)
+
+    def test_update_fuzzy_matching_no_cascading(self):
+        cat = catalog.Catalog()
+        cat.add('fo', 'Voh')
+        cat.add('foo', 'Vohe')
+        tmpl = catalog.Catalog()
+        tmpl.add('fo')
+        tmpl.add('foo')
+        tmpl.add('fooo')
+        cat.update(tmpl)
+        assert 'fo' in cat
+        assert 'foo' in cat
+
+        self.assertEqual('Voh', cat['fo'].string)
+        self.assertEqual(False, cat['fo'].fuzzy)
+        self.assertEqual('Vohe', cat['foo'].string)
+        self.assertEqual(False, cat['foo'].fuzzy)
+        self.assertEqual('Vohe', cat['fooo'].string)
+        self.assertEqual(True, cat['fooo'].fuzzy)
+
     def test_update_without_fuzzy_matching(self):
         cat = catalog.Catalog()
         cat.add('fo', 'Voh')
@@ -140,6 +174,17 @@
         cat.update(tmpl, no_fuzzy_matching=True)
         self.assertEqual(2, len(cat.obsolete))
 
+    def test_update_no_template_mutation(self):
+        tmpl = catalog.Catalog()
+        tmpl.add('foo')
+        cat1 = catalog.Catalog()
+        cat1.add('foo', 'Voh')
+        cat1.update(tmpl)
+        cat2 = catalog.Catalog()
+        cat2.update(tmpl)
+
+        self.assertEqual(None, cat2['foo'].string)
+        self.assertEqual(False, cat2['foo'].fuzzy)
 
 def suite():
     suite = unittest.TestSuite()