Revert 54813 for 2.5.1 release. Can be applied after 2.5 branch is unfrozen.

Objects/frameobject.c

@@ -68,7 +68,7 @@ frame_setlineno(PyFrameObject *f, PyObject* p_new_lineno)
 	int new_lineno = 0;		/* The new value of f_lineno */
 	int new_lasti = 0;		/* The new value of f_lasti */
 	int new_iblock = 0;		/* The new value of f_iblock */
-	unsigned char *code = NULL;	/* The bytecode for the frame... */
+	char *code = NULL;		/* The bytecode for the frame... */
 	Py_ssize_t code_len = 0;	/* ...and its length */
 	char *lnotab = NULL;		/* Iterating over co_lnotab */
 	Py_ssize_t lnotab_len = 0;	/* (ditto) */
@@ -85,7 +85,7 @@ frame_setlineno(PyFrameObject *f, PyObject* p_new_lineno)
 	int blockstack[CO_MAXBLOCKS];	/* Walking the 'finally' blocks */
 	int in_finally[CO_MAXBLOCKS];	/* (ditto) */
 	int blockstack_top = 0;		/* (ditto) */
-	unsigned char setup_op = 0;	/* (ditto) */
+	int setup_op = 0;               /* (ditto) */
 
 	/* f_lineno must be an integer. */
 	if (!PyInt_Check(p_new_lineno)) {

Python/ceval.c

@@ -662,7 +662,7 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
 #define STACKADJ(n)	{ (void)(BASIC_STACKADJ(n), \
                                lltrace && prtrace(TOP(), "stackadj")); \
                                assert(STACK_LEVEL() <= co->co_stacksize); }
-#define EXT_POP(STACK_POINTER) (lltrace && prtrace((STACK_POINTER)[-1], "ext_pop"), *--(STACK_POINTER))
+#define EXT_POP(STACK_POINTER) (lltrace && prtrace(*(STACK_POINTER), "ext_pop"), *--(STACK_POINTER))
 #else
 #define PUSH(v)		BASIC_PUSH(v)
 #define POP()		BASIC_POP()