bpo-33803: Fix a crash in hamt.c (GH-7504) (GH-7505)

(cherry picked from commit 378c53cc3187dba57c7560ccc2557f516c8a7bc8)

Co-authored-by: Yury Selivanov <yury@magic.io>

diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-06-07-20-18-38.bpo-33803.n-Nq6_.rst b/Misc/NEWS.d/next/Core and Builtins/2018-06-07-20-18-38.bpo-33803.n-Nq6_.rst
new file mode 100644 (file)
index 0000000..9cb8457
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2018-06-07-20-18-38.bpo-33803.n-Nq6_.rst
@@ -0,0 +1,2 @@
+Fix a crash in hamt.c caused by enabling GC tracking for an object that
+hadn't all of its fields set to NULL.

diff --git a/Python/hamt.c b/Python/hamt.c
index 52171222b005ee82602922949010fbbdaf730275..f8bce5961afc61f87bbc33f715d0ab8c09852d30 100644 (file)
--- a/Python/hamt.c
+++ b/Python/hamt.c
@@ -2476,6 +2476,8 @@ hamt_alloc(void)
     if (o == NULL) {
         return NULL;
     }
+    o->h_count = 0;
+    o->h_root = NULL;
     o->h_weakreflist = NULL;
     PyObject_GC_Track(o);
     return o;