Apply diff3.txt from SF patch http://www.python.org/sf/536241

If a str or unicode method returns the original object,
make sure that for str and unicode subclasses the original
will not be returned.

This should prevent SF bug http://www.python.org/sf/460020
from reappearing.

1 files changed, 19 insertions, 0 deletions

diff --git a/Lib/test/test_string.py b/Lib/test/test_string.py
index 4c5a60a..8f0ea47 100644
--- a/Lib/test/test_string.py
+++ b/Lib/test/test_string.py
@@ -22,6 +22,25 @@ def test(name, input, output, *args):
     except:
         value = sys.exc_type
         f = name
+    if value == output:
+        # if the original is returned make sure that
+        # this doesn't happen with subclasses
+        if value is input:
+            class ssub(str):
+                def __repr__(self):
+                    return 'ssub(%r)' % str.__repr__(self)
+            input = ssub(input)
+            try:
+                f = getattr(input, name)
+                value = apply(f, args)
+            except AttributeError:
+                f = getattr(string, name)
+                value = apply(f, (input,) + args)
+            if value is input:
+                if verbose:
+                   print 'no'
+                print '*',f, `input`, `output`, `value`
+                return
     if value != output:
         if verbose:
             print 'no'