Have exnToString handle exceptions whose str representation is empty.

src/utils.py

@@ -537,7 +537,11 @@ def safeEval(s, namespace={'True': True, 'False': False, 'None': None}):
 
 def exnToString(e):
     """Turns a simple exception instance into a string (better than str(e))"""
-    return '%s: %s' % (e.__class__.__name__, e)
+    strE = str(e)
+    if strE:
+        return '%s: %s' % (e.__class__.__name__, strE)
+    else:
+        return e.__class__.__name__
 
 class IterableMap(object):
     """Define .iteritems() in a class and subclass this to get the other iters.

test/test_utils.py

@@ -33,6 +33,16 @@ import sets
 import supybot.utils as utils
 
 class UtilsTest(SupyTestCase):
+    def testExnToString(self):
+        try:
+            raise KeyError, 1
+        except Exception, e:
+            self.assertEqual(utils.exnToString(e), 'KeyError: 1')
+        try:
+            raise EOFError
+        except Exception, e:
+            self.assertEqual(utils.exnToString(e), 'EOFError')
+
     def testMatchCase(self):
         f = utils.matchCase
         self.assertEqual('bar', f('foo', 'bar'))