From: Brett Cannon <bcannon@gmail.com>
Date: Tue, 13 Jun 2006 21:50:24 +0000 (+0000)
Subject: Classic class that defined ``def __coerce__(self, other): return other, self``
X-Git-Tag: v2.4.4c1~180
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df43ce33fb0a1720c986d82cafb0be8cf60ba844;p=thirdparty%2FPython%2Fcpython.git

Classic class that defined ``def __coerce__(self, other): return other, self``
would infinitely recourse and segfault the interpreter.  Now a recursion check
occurs after a coercion.

Backport of fix for bug #992017.
---

diff --git a/Misc/NEWS b/Misc/NEWS
index f83d112fe62b..005255fdaa7c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@ What's New in Python 2.4.4c1?
 Core and builtins
 -----------------
 
+- Bug #992017: A classic class that defined a __coerce__() method that returned
+  its arguments swapped would infinitely recurse and segfault the interpreter.
+
 - Bug #532646: The object set to the __call__ attribute has its own __call__
   attribute checked; this continues until the attribute can no longer be found
   or segfaulting.  Recursion limit is now followed.
diff --git a/Objects/classobject.c b/Objects/classobject.c
index 187f8d0648c1..bbd4c6d8f53c 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -1428,10 +1428,13 @@ half_binop(PyObject *v, PyObject *w, char *opname, binaryfunc thisfunc,
 		 * argument */
 		result = generic_binary_op(v1, w, opname);
 	} else {
+		if (Py_EnterRecursiveCall(" after coercion"))
+		    return NULL;
 		if (swapped)
 			result = (thisfunc)(w, v1);
 		else
 			result = (thisfunc)(v1, w);
+		Py_LeaveRecursiveCall();
 	}
 	Py_DECREF(coerced);
 	return result;