From d297f1ad78f1058c62bf47c2f1e2c2488f7e9d25 Mon Sep 17 00:00:00 2001
From: Georg Brandl <georg@python.org>
Date: Sun, 15 Jun 2008 19:53:12 +0000
Subject: [PATCH] #3117: backport r55087, fixes segfault with lambda (None,):
 None.

---
 Lib/test/test_grammar.py | 1 +
 Python/ast.c             | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index 6a9e5124c69..09ccde7002d 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -277,6 +277,7 @@ l5 = lambda x, y, z=2: x + y + z
 verify(l5(1, 2) == 5)
 verify(l5(1, 2, 3) == 6)
 check_syntax("lambda x: x = 2")
+check_syntax("lambda (None,): None")
 
 ### stmt: simple_stmt | compound_stmt
 # Tested below
diff --git a/Python/ast.c b/Python/ast.c
index c7fd8bcc960..057b64df325 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -249,6 +249,8 @@ PyAST_FromNode(const node *n, PyCompilerFlags *flags, const char *filename,
 		    goto error;
                 asdl_seq_SET(stmts, 0, Pass(n->n_lineno, n->n_col_offset,
                                             arena));
+                if (!asdl_seq_GET(stmts, 0))
+                    goto error;
                 return Interactive(stmts, arena);
             }
             else {
@@ -679,6 +681,8 @@ ast_for_arguments(struct compiling *c, const node *n)
 		    if (NCH(ch) != 1) {
 			/* We have complex arguments, setup for unpacking. */
 			asdl_seq_SET(args, k++, compiler_complex_args(c, ch));
+			if (!asdl_seq_GET(args, k-1))
+			    goto error;
 		    } else {
 			/* def foo((x)): setup for checking NAME below. */
 			/* Loop because there can be many parens and tuple