Backport tim_one's checkin of version 2.302:

SF bug #496549 -Qnew and in-place division "/=".

eval_frame():  Under -Qnew, INPLACE_DIVIDE wasn't getting handed off to
INPLACE_TRUE_DIVIDE (like BINARY_DIVIDE was getting handed off to
BINARY_TRUE_DIVIDE).

Bugfix candidate.

Python/ceval.c

@@ -1091,9 +1091,22 @@ eval_frame(PyFrameObject *f)
 			break;
 
 		case INPLACE_DIVIDE:
+			if (!_Py_QnewFlag) {
+				w = POP();
+				v = POP();
+				x = PyNumber_InPlaceDivide(v, w);
+				Py_DECREF(v);
+				Py_DECREF(w);
+				PUSH(x);
+				if (x != NULL) continue;
+				break;
+			}
+			/* -Qnew is in effect:  fall through to
+			   INPLACE_TRUE_DIVIDE */
+		case INPLACE_TRUE_DIVIDE:
 			w = POP();
 			v = POP();
-			x = PyNumber_InPlaceDivide(v, w);
+			x = PyNumber_InPlaceTrueDivide(v, w);
 			Py_DECREF(v);
 			Py_DECREF(w);
 			PUSH(x);
@@ -1110,16 +1123,6 @@ eval_frame(PyFrameObject *f)
 			if (x != NULL) continue;
 			break;
 
-		case INPLACE_TRUE_DIVIDE:
-			w = POP();
-			v = POP();
-			x = PyNumber_InPlaceTrueDivide(v, w);
-			Py_DECREF(v);
-			Py_DECREF(w);
-			PUSH(x);
-			if (x != NULL) continue;
-			break;
-
 		case INPLACE_MODULO:
 			w = POP();
 			v = POP();