Fixed #1852 -- Improved TemplateSyntaxError to display the original e…

…xception if str() of the exception raises an exception in itself. Thanks, nnorwitz@google.com

git-svn-id: http://code.djangoproject.com/svn/django/trunk@2906 bcc190cf-cafb-0310-a4f2-bffc1f526a37

AUTHORS

@@ -88,6 +88,7 @@ answer newbie questions, and generally made Django that much better:
     Robin Munn <http://www.geekforgod.com/>
     Nebojša Dorđević
     Sam Newman <http://www.magpiebrain.com/>
+    Neal Norwitz <nnorwitz@google.com>
     oggie rob <oz.robharvey@gmail.com>
     pgross@thoughtworks.com
     phaedo <http://phaedo.cx/>

django/template/__init__.py

@@ -91,7 +91,20 @@
 builtins = []
 
 class TemplateSyntaxError(Exception):
-    pass
+    def __str__(self):
+        try:
+            import cStringIO as StringIO
+        except ImportError:
+            import StringIO
+        output = StringIO.StringIO()
+        output.write(Exception.__str__(self))
+        # Check if we wrapped an exception and print that too.
+        if hasattr(self, 'exc_info'):
+            import traceback
+            output.write('\n\nOriginal ')
+            e = self.exc_info
+            traceback.print_exception(e[0], e[1], e[2], 500, output)
+        return output.getvalue()
 
 class TemplateDoesNotExist(Exception):
     pass