Vladimir Marangozov's long-awaited malloc restructuring. For more comments, read the patches@python.org archives. For documentation read the comments in mymalloc.h and objimpl.h. (This is not exactly what Vladimir posted to the patches list; I've made a few changes, and Vladimir sent me a fix in private email for a problem that only occurs in debug mode. I'm also holding back on his change to main.c, which seems unnecessary to me.)

--- a/Python/ceval.c	Wed May 03 22:34:12 2000 +0000
+++ b/Python/ceval.c	Wed May 03 23:44:39 2000 +0000
@@ -2558,7 +2558,8 @@
 		class);
 	
 	Py_DECREF(arg);
-	PyMem_XDEL(k);
+	if (k != NULL)
+		PyMem_DEL(k);
 	
 	return result;
 }