Fix issubclass() call that fails on string exceptions.

lib/python/Zope/__init__.py

@@ -99,17 +99,17 @@ def zpublisher_exception_hook(
     published, REQUEST, t, v, traceback,
     # static
     StringType=type(''),
-    lower=string.lower,
     ConflictError=ZODB.POSException.ConflictError,
     ListType=type([]),
     ):
     try:
-        if ((type(t) is StringType and
-             lower(t) in ('unauthorized', 'redirect'))
-            or t is SystemExit):
+        if isinstance(t, StringType):
+            if t.lower() in ('unauthorized', 'redirect'):
+                raise
+        else:
+            if t is SystemExit:
                 raise
             if issubclass(t, ConflictError):
-            # now what
                 # First, we need to close the current connection. We'll
                 # do this by releasing the hold on it. There should be
                 # some sane protocol for this, but for now we'll use
@@ -117,9 +117,10 @@ def zpublisher_exception_hook(
                 global conflict_errors
                 conflict_errors = conflict_errors + 1
                 method_name = REQUEST.get('PATH_INFO', '')
-            err = ('ZODB conflict error at %s (%s conflicts since startup '
-                   'at %s)')
-            LOG(err % (method_name, conflict_errors, startup_time), INFO, '')
+                err = ('ZODB conflict error at %s '
+                       '(%s conflicts since startup at %s)')
+                LOG(err % (method_name, conflict_errors, startup_time),
+                    INFO, '')
                 LOG('Conflict traceback', BLATHER, '', error=sys.exc_info())
                 raise ZPublisher.Retry(t, v, traceback)
             if t is ZPublisher.Retry: v.reraise()