--- a/tests/test_push_command.py
+++ b/tests/test_push_command.py
@@ -8,6 +8,7 @@ from mercurial import hg
 from mercurial import node
 from mercurial import ui
 from mercurial import revlog
+from mercurial import util as hgutil
 
 import wrappers
 import test_util
@@ -404,6 +405,23 @@ class PushTests(test_util.TestBase):
         self.assertEqual(tip.parents()[0]['alpha'].flags(), expected_flags)
         self.assertEqual(tip['alpha'].flags(), '')
 
+    def test_push_outdated_base_text(self):
+        self.test_push_two_revs()
+        changes = [('adding_file', 'adding_file', 'different_content', ),
+                   ]
+        self.commitchanges(changes, parent='tip')
+        self.pushrevisions()
+        changes = [('adding_file', 'adding_file',
+                    'even_more different_content', ),
+                   ]
+        self.commitchanges(changes, parent=3)
+        try:
+            self.pushrevisions()
+            assert False, 'This should have aborted!'
+        except hgutil.Abort, e:
+            self.assertEqual(e.args[0],
+                             'Base text was out of date, maybe rebase?')
+
 
 def suite():
     test_classes = [PushTests, PushOverSvnserveTests]

--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -140,7 +140,7 @@ class TestBase(unittest.TestCase):
         entries.sort()
         return entries
 
-    def commitchanges(self, changes):
+    def commitchanges(self, changes, parent='tip'):
         """Commit changes to mercurial directory
 
         'changes' is a sequence of tuples (source, dest, data). It can look
@@ -153,7 +153,7 @@ class TestBase(unittest.TestCase):
         - (source, None, None) to remove source.
         """
         repo = self.repo
-        parentctx = repo['tip']
+        parentctx = repo[parent]
 
         changed, removed = [], []
         for source, dest, newdata in changes:
@@ -187,7 +187,7 @@ class TestBase(unittest.TestCase):
                              '2008-10-07 20:59:48 -0500')
         nodeid = repo.commitctx(ctx)
         repo = self.repo
-        hg.update(repo, nodeid)
+        hg.clean(repo, nodeid)
         return nodeid
 
     def assertchanges(self, changes, ctx):