SF bug 567538: Generator can crash the interpreter (Finn Bock).

gvanrossum · gvanrossum · commit c5fe5eb8d265 · 2002-06-12T03:45:21.000Z
This was a simple typo.  Strange that the compiler didn't catch it!
Instead of WHY_CONTINUE, two tests used CONTINUE_LOOP, which isn't a
why_code at all, but an opcode; but even though 'why' is declared as
an enum, comparing it to an int is apparently not even worth a
warning -- not in gcc, and not in VC++. :-(

Will fix in 2.2 too.
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
@@ -805,6 +805,26 @@
 ...         yield 2             # because it's a generator
 Traceback (most recent call last):
 SyntaxError: 'return' with argument inside generator (<string>, line 8)
+
+This one caused a crash (see SF bug 567538):
+
+>>> def f():
+...     for i in range(3):
+...         try:
+...             continue
+...         finally:
+...             yield i
+... 
+>>> g = f()
+>>> print g.next()
+0
+>>> print g.next()
+1
+>>> print g.next()
+2
+>>> print g.next()
+Traceback (most recent call last):
+StopIteration
 """
 
 # conjoin is a simple backtracking generator, named in honor of Icon's
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -6,6 +6,9 @@ Type/class unification and new-style classes
 
 Core and builtins
 
+- Fixed a bug with a continue inside a try block and a yield in the
+  finally clause.  [SF bug 567538]
+
 - Most builtin sequences now support "extended slices", i.e. slices
   with a third "stride" parameter.  For example, "range(10)[1:6:2]"
   evaluates to [1, 3, 5].
diff --git a/Python/ceval.c b/Python/ceval.c
@@ -1543,7 +1543,7 @@ eval_frame(PyFrameObject *f)
 				why = (enum why_code) PyInt_AsLong(v);
 				if (why == WHY_RETURN ||
 				    why == WHY_YIELD ||
-				    why == CONTINUE_LOOP)
+				    why == WHY_CONTINUE)
 					retval = POP();
 			}
 			else if (PyString_Check(v) || PyClass_Check(v)) {
@@ -2293,7 +2293,7 @@ eval_frame(PyFrameObject *f)
 				}
 				else {
 					if (why == WHY_RETURN ||
-					    why == CONTINUE_LOOP)
+					    why == WHY_CONTINUE)
 						PUSH(retval);
 					v = PyInt_FromLong((long)why);
 					PUSH(v);
