Fix for issue #1888 (merge from branch).

doc/CHANGES.txt

@@ -58,6 +58,11 @@ Zope Changes
       - DateIndex now properly removes documents from both indexes if
         the value is None
 
+      - Collector #1888: Some parts of the TALInterpreter would not pass a 
+        default when  translating, yet expect a string back. This would cause 
+        an error (usually "NoneType has no attribute 'replace'") in the case 
+        the message was not translated.
+        
   Zope 2.8.1 (2005/08/11)
 
     Features added

lib/python/TAL/TALInterpreter.py

@@ -531,7 +531,8 @@ class TALInterpreter:
             return
         if isinstance(text, I18nMessageTypes):
             # Translate this now.
-            text = self.engine.translate(text.domain, text, text.mapping)
+            text = self.engine.translate(text.domain, text, 
+                                         text.mapping, text.default)
         s = cgi.escape(text)
         self._stream_write(s)
         i = s.rfind('\n')
@@ -571,8 +572,9 @@ class TALInterpreter:
             # evaluate() does not do any I18n, so we do it here.
             if isinstance(value, I18nMessageTypes):
                 # Translate this now.
+                # XXX
                 value = self.engine.translate(value.domain, value,
-                                              value.mapping)
+                                              value.mapping, value.default)
 
             if not structure:
                 value = cgi.escape(ustr(value))

lib/python/TAL/tests/test_talinterpreter.py

@@ -70,6 +70,7 @@ class I18NCornerTestCase(TestCaseBase):
         self.engine.setLocal('foo', MessageID('FoOvAlUe', 'default'))
         self.engine.setLocal('bar', 'BaRvAlUe')
         self.engine.setLocal('raw', ' \tRaW\n ')
+        self.engine.setLocal('noxlt', MessageID("don't translate me"))
 
     def _check(self, program, expected):
         result = StringIO()
@@ -286,6 +287,17 @@ class I18NCornerTestCase(TestCaseBase):
             "Foo <span tal:replace='bar' i18n:name='bar' /></div>")
         self._check(program, u"<div>FOO \u00C0</div>\n")
 
+    def test_for_untranslated_messageid_simple(self):
+        program, macros = self._compile('<span tal:content="noxlt"/>')
+        self._check(program, "<span>don't translate me</span>\n")
+        
+    def test_for_untranslated_messageid_i18nname(self):
+        program, macros = self._compile(
+            '<div i18n:translate="" >'
+            '<span tal:replace="python: noxlt" i18n:name="foo_name"/>'
+            '</div>')
+        self._check(program, "<div>don't translate me</div>\n")
+
 
 class I18NErrorsTestCase(TestCaseBase):