Generators had their throw() method allowing string exceptions. That's a

no-no.

Fixes issue #1147.  Need to fix 2.5 to raise a proper warning if a string
exception is passed in.

Lib/test/test_generators.py

@@ -1622,7 +1622,7 @@ ValueError: 7
 >>> f().throw("abc")     # throw on just-opened generator
 Traceback (most recent call last):
   ...
-abc
+TypeError: exceptions must be classes, or instances, not str
 
 Now let's try closing a generator:
 

Misc/NEWS

@@ -12,6 +12,9 @@ What's New in Python 2.6 alpha 1?
 Core and builtins
 -----------------
 
+- Issue #1147: Exceptions were directly allowing string exceptions in their
+  throw() method even though string exceptions no longer allowed.
+
 - Issue #1096: Prevent a segfault from getting the repr of a very deeply nested
   list by using the recursion counter.
 

Objects/genobject.c

@@ -252,10 +252,7 @@ gen_throw(PyGenObject *gen, PyObject *args)
 			Py_INCREF(typ);
 		}
 	}
-
-	/* Allow raising builtin string exceptions */
-
-	else if (!PyString_CheckExact(typ)) {
+	else {
 		/* Not something you can raise.  throw() fails. */
 		PyErr_Format(PyExc_TypeError,
 			     "exceptions must be classes, or instances, not %s",