[pypy-svn] pypy default: (fijal, arigo)

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r40978:8b936960cb37
Date: 2011-01-20 12:16 +0100
http://bitbucket.org/pypy/pypy/changeset/8b936960cb37/

Log:	(fijal, arigo)

	Check the return type of __format__().

diff --git a/pypy/module/__builtin__/operation.py b/pypy/module/__builtin__/operation.py
--- a/pypy/module/__builtin__/operation.py
+++ b/pypy/module/__builtin__/operation.py
@@ -262,8 +262,6 @@
 function).  Note that classes are callable."""
     return space.callable(w_object)
 
-def format(space, w_obj, w_format_spec=NoneNotWrapped):
+def format(space, w_obj, w_format_spec=""):
     """Format a obj according to format_spec"""
-    if w_format_spec is None:
-        w_format_spec = space.wrap("")
     return space.format(w_obj, w_format_spec)

diff --git a/pypy/objspace/descroperation.py b/pypy/objspace/descroperation.py
--- a/pypy/objspace/descroperation.py
+++ b/pypy/objspace/descroperation.py
@@ -316,11 +316,18 @@
     def format(space, w_obj, w_format_spec):
         w_descr = space.lookup(w_obj, '__format__')
         if w_descr is None:
-            typename = space.type(w_obj).getname(space, '?')
+            typename = space.type(w_obj).getname(space)
             raise operationerrfmt(space.w_TypeError,
                                   "'%s' object does not define __format__",
                                   typename)
-        return space.get_and_call_function(w_descr, w_obj, w_format_spec)
+        w_res = space.get_and_call_function(w_descr, w_obj, w_format_spec)
+        if not space.is_true(space.isinstance(w_res, space.w_basestring)):
+            typename = space.type(w_obj).getname(space)
+            restypename = space.type(w_res).getname(space)
+            raise operationerrfmt(space.w_TypeError,
+                "%s.__format__ must return string or unicode, not %s",
+                                  typename, restypename)
+        return w_res
 
     def pow(space, w_obj1, w_obj2, w_obj3):
         w_typ1 = space.type(w_obj1)