#7050 fix a SystemError when using tuple unpacking and augmented assignment
diff --git a/Lib/test/test_augassign.py b/Lib/test/test_augassign.py
index 24aa2b7..a5b7cc4 100644
--- a/Lib/test/test_augassign.py
+++ b/Lib/test/test_augassign.py
@@ -24,6 +24,9 @@
# new-style division (with -Qnew)
self.assertEquals(x, 3.0)
+ def test_with_unpacking(self):
+ self.assertRaises(SyntaxError, compile, "x, b += 3", "<test>", "exec")
+
def testInList(self):
x = [2]
x[0] += 1
diff --git a/Misc/NEWS b/Misc/NEWS
index dc54329..bafb0ab 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
Core and Builtins
-----------------
+- Issue #7050: Fix a SystemError when trying to use unpacking and augmented
+ assignment.
+
- Issue #5329: Fix os.popen* regression from 2.5 with commands as a
sequence running through the shell. Patch by Jean-Paul Calderone
and Jani Hakala.
diff --git a/Python/ast.c b/Python/ast.c
index 2f975ac..3422c2e 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -2097,6 +2097,19 @@
return NULL;
if(!set_context(c, expr1, Store, ch))
return NULL;
+ /* set_context checks that most expressions are not the left side.
+ Augmented assignments can only have a name, a subscript, or an
+ attribute on the left, though, so we have to explicitly check for
+ those. */
+ switch (expr1->kind) {
+ case Name_kind:
+ case Attribute_kind:
+ case Subscript_kind:
+ break;
+ default:
+ ast_error(ch, "illegal expression for augmented assignment");
+ return NULL;
+ }
ch = CHILD(n, 2);
if (TYPE(ch) == testlist)