commit 5cadd3fe3aead1b5bee1438dc03383d6739d4209
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Mon Jan 20 15:06:40 2020 -0800
committer GitHub <noreply@github.com> Mon Jan 20 15:06:40 2020 -0800
tree f43a6fad9c24094f3432b275ebc2bd57c4cb882b
parent 6aeed01901d020363e383821b38614816d0b4032

bpo-39386: Prevent double awaiting of async iterator (GH-18081)

(cherry picked from commit a96e06db77dcbd3433d39761ddb4615d7d96284a)

Co-authored-by: Andrew Svetlov <andrew.svetlov@gmail.com>

Objects/genobject.c

diff --git a/Objects/genobject.c b/Objects/genobject.c
index 5643553..72aa872 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -1533,7 +1533,9 @@
     PyObject *result;
 
     if (o->ags_state == AWAITABLE_STATE_CLOSED) {
-        PyErr_SetNone(PyExc_StopIteration);
+        PyErr_SetString(
+            PyExc_RuntimeError,
+            "cannot reuse already awaited __anext__()/asend()");
         return NULL;
     }
 
@@ -1576,7 +1578,9 @@
     PyObject *result;
 
     if (o->ags_state == AWAITABLE_STATE_CLOSED) {
-        PyErr_SetNone(PyExc_StopIteration);
+        PyErr_SetString(
+            PyExc_RuntimeError,
+            "cannot reuse already awaited __anext__()/asend()");
         return NULL;
     }
 
@@ -1810,7 +1814,9 @@
 
     if (f == NULL || f->f_stacktop == NULL ||
             o->agt_state == AWAITABLE_STATE_CLOSED) {
-        PyErr_SetNone(PyExc_StopIteration);
+        PyErr_SetString(
+            PyExc_RuntimeError,
+            "cannot reuse already awaited aclose()/athrow()");
         return NULL;
     }
 
@@ -1932,7 +1938,9 @@
     PyObject *retval;
 
     if (o->agt_state == AWAITABLE_STATE_CLOSED) {
-        PyErr_SetNone(PyExc_StopIteration);
+        PyErr_SetString(
+            PyExc_RuntimeError,
+            "cannot reuse already awaited aclose()/athrow()");
         return NULL;
     }