Ticket #19923: 19923-2.diff

django/core/management/base.py

@@ -241 +241 @@
         except Exception as e:
             # self.stderr is not guaranteed to be set here
             stderr = getattr(self, 'stderr', OutputWrapper(sys.stderr, self.style.ERROR))
-            if options.traceback:
+            if options.traceback or not isinstance(e, CommandError):
                 stderr.write(traceback.format_exc())
             else:
                 stderr.write('%s: %s' % (e.__class__.__name__, e))

docs/ref/django-admin.txt

@@ -1342 +1342 @@
     django-admin.py syncdb --traceback
 
 By default, ``django-admin.py`` will show a simple error message whenever an
-error occurs. If you specify ``--traceback``, ``django-admin.py``  will
-output a full stack trace whenever an exception is raised.
+:class:`~django.core.management.CommandError` occurs, but a full stack trace
+for any other exception. If you specify ``--traceback``, ``django-admin.py``
+will also output a full stack trace when a ``CommandError`` is raised.
 
 .. django-admin-option:: --verbosity
 

tests/admin_scripts/tests.py

@@ -16 +16 @@
 
 from django import conf, bin, get_version
 from django.conf import settings
-from django.core.management import BaseCommand
+from django.core.management import BaseCommand, CommandError
 from django.db import connection
 from django.test.simple import DjangoTestSuiteRunner
 from django.utils import unittest
@@ -1297 +1297 @@
         Also test proper traceback display.
         """
         command = BaseCommand()
-        command.execute = lambda args: args  # This will trigger TypeError
+        def raise_command_error(*args, **kwargs):
+            raise CommandError("Custom error")
 
         old_stderr = sys.stderr
         sys.stderr = err = StringIO()
         try:
+            command.execute = lambda args: args  # This will trigger TypeError
             with self.assertRaises(SystemExit):
                 command.run_from_argv(['', ''])
             err_message = err.getvalue()
-            self.assertNotIn("Traceback", err_message)
+            # Exceptions other than CommandError automatically output the traceback
+            self.assertIn("Traceback", err_message)
             self.assertIn("TypeError", err_message)
 
+            command.execute = raise_command_error
+            err.truncate(0)
+            with self.assertRaises(SystemExit):
+                command.run_from_argv(['', ''])
+            err_message = err.getvalue()
+            self.assertNotIn("Traceback", err_message)
+            self.assertIn("CommandError", err_message)
+
+            err.truncate(0)
             with self.assertRaises(SystemExit):
                 command.run_from_argv(['', '', '--traceback'])
             err_message = err.getvalue()
             self.assertIn("Traceback (most recent call last)", err_message)
-            self.assertIn("TypeError", err_message)
+            self.assertIn("CommandError", err_message)
         finally:
             sys.stderr = old_stderr