SF bug #488687 reported by Neal Norwitz The error for assignment to __debug__ used ste->ste_opt_lineno instead of n->n_lineno. The latter was at best incorrect; often the slot was uninitialized. Two fixes here: Use the correct lineno for the error. Initialize ste_opt_lineno in PySymtable_New(); while there are no current cases where it is referenced unless it has already been assigned to, there is no harm in initializing it.

--- a/Python/compile.c	Tue Dec 04 01:11:32 2001 +0000
+++ b/Python/compile.c	Tue Dec 04 02:41:46 2001 +0000
@@ -5464,7 +5464,7 @@
 				PyErr_SetString(PyExc_SyntaxError, 
 						ASSIGN_DEBUG);
 				PyErr_SyntaxLocation(st->st_filename,
-					     st->st_cur->ste_opt_lineno);
+						     n->n_lineno);
 				st->st_errors++;
 			}
 			symtable_add_def(st, STR(tmp), DEF_LOCAL | def_flag);