Rev 2855: Fix "unprintable error" message for BzrCheckError and others in http://sourcefrog.net/bzr/exception-keyerrors

[Martin Pool]

At http://sourcefrog.net/bzr/exception-keyerrors

------------------------------------------------------------
revno: 2855
revision-id: mbp at sourcefrog.net-20070925062946-1tlmmt604lf9bllm
parent: pqm at pqm.ubuntu.com-20070924212812-g325vvenhnfktgbh
committer: Martin Pool <mbp at sourcefrog.net>
branch nick: exception-keyerrors
timestamp: Tue 2007-09-25 16:29:46 +1000
message:
  Fix "unprintable error" message for BzrCheckError and others
modified:
  NEWS                           NEWS-20050323055033-4e00b5db738777ff
  bzrlib/errors.py               errors.py-20050309040759-20512168c4e14fbd
  bzrlib/tests/test_errors.py    test_errors.py-20060210110251-41aba2deddf936a8
=== modified file 'NEWS'
--- a/NEWS	2007-09-24 09:40:01 +0000
+++ b/NEWS	2007-09-25 06:29:46 +0000
@@ -79,6 +79,10 @@
      contains a symbolic link.
      (Vincent Ladeuil, #141382).
 
+   * Fix 'unprintable error' message when displaying BzrCheckError and 
+     some other exceptions on Python 2.5.
+     (Martin Pool, #144633)
+
    * HttpServer and FtpServer need to be closed properly or a listening socket
      will remain opened.
      (Vincent Ladeuil, #140055)

=== modified file 'bzrlib/errors.py'
--- a/bzrlib/errors.py	2007-09-13 01:54:49 +0000
+++ b/bzrlib/errors.py	2007-09-25 06:29:46 +0000
@@ -95,7 +95,11 @@
         try:
             fmt = self._get_format_string()
             if fmt:
-                s = fmt % self.__dict__
+                d = (self.__dict__)
+                # special case: python2.5 puts the 'message' attribute in a
+                # slot, so it isn't seen in __dict__
+                d['message'] = getattr(self, 'message', 'dummy message')
+                s = fmt % d
                 # __str__() should always return a 'str' object
                 # never a 'unicode' object.
                 if isinstance(s, unicode):
@@ -783,8 +787,8 @@
     # New code should prefer to raise specific subclasses
     def __init__(self, message):
         # Python 2.5 uses a slot for StandardError.message,
-        # so use a different variable name
-        # so it is exposed in self.__dict__
+        # so use a different variable name.  We now work around this in
+        # BzrError.__str__, but this member name is kept for compatability.
         self.msg = message
 
 

=== modified file 'bzrlib/tests/test_errors.py'
--- a/bzrlib/tests/test_errors.py	2007-08-30 08:11:54 +0000
+++ b/bzrlib/tests/test_errors.py	2007-09-25 06:29:46 +0000
@@ -361,6 +361,15 @@
         self.assertEqual(
             "Container has multiple records with the same name: n\xc3\xa5me",
             str(e))
+        
+    def test_check_error(self):
+        # This has a member called 'message', which is problematic in
+        # python2.5 because that is a slot on the base Exception class
+        e = errors.BzrCheckError('example check failure')
+        self.assertEqual(
+            "Internal check failed: example check failure",
+            str(e))
+        self.assertTrue(e.internal_error)
 
 
 class PassThroughError(errors.BzrError):