diff -r 1d9d29d4813a -r 0767c2f624c6 tests/blackbox-readonly-dispatch.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/blackbox-readonly-dispatch.py	Tue Mar 08 20:52:57 2016 +0000
@@ -0,0 +1,36 @@
+from __future__ import absolute_import, print_function
+import os
+from mercurial import (
+    dispatch,
+)
+
+def testdispatch(cmd):
+    """Simple wrapper around dispatch.dispatch()
+
+    Prints command and result value, but does not handle quoting.
+    """
+    print("running: %s" % (cmd,))
+    req = dispatch.request(cmd.split())
+    result = dispatch.dispatch(req)
+    print("result: %r" % (result,))
+
+# create file 'foo', add and commit
+f = open('foo', 'wb')
+f.write('foo\n')
+f.close()
+testdispatch("add foo")
+testdispatch("commit -m commit1 -d 2000-01-01 foo")
+
+# append to file 'foo' and commit
+f = open('foo', 'ab')
+f.write('bar\n')
+f.close()
+# remove blackbox.log directory (proxy for readonly log file)
+os.rmdir(".hg/blackbox.log")
+# replace it with the real blackbox.log file
+os.rename(".hg/blackbox.log-", ".hg/blackbox.log")
+testdispatch("commit -m commit2 -d 2000-01-02 foo")
+
+# check 88803a69b24 (fancyopts modified command table)
+testdispatch("log -r 0")
+testdispatch("log -r tip")