From 98e818b8e37692faae15c792397765b0bc0ef7ea Mon Sep 17 00:00:00 2001
From: Victor Stinner <victor.stinner@gmail.com>
Date: Tue, 5 Nov 2013 18:07:34 +0100
Subject: [PATCH] Issue #19437: Fix compiler_class(), handle
 compiler_lookup_arg() failure

---
 Python/compile.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Python/compile.c b/Python/compile.c
index 32465f71692..8b00211c9fd 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1772,6 +1772,10 @@ compiler_class(struct compiler *c, stmt_ty s)
             }
             i = compiler_lookup_arg(c->u->u_cellvars, str);
             Py_DECREF(str);
+            if (i < 0) {
+                compiler_exit_scope(c);
+                return 0;
+            }
             assert(i == 0);
             /* Return the cell where to store __class__ */
             ADDOP_I(c, LOAD_CLOSURE, i);