Issue 553

Two missing calls to PyObject_GC_UnTrack()

c/_cffi_backend.c

@@ -1938,6 +1938,7 @@ static void cdataowninggc_dealloc(CDataObject *cd)
 static void cdatafrombuf_dealloc(CDataObject *cd)
 {
     Py_buffer *view = ((CDataObject_frombuf *)cd)->bufferview;
+    PyObject_GC_UnTrack(cd);
     cdata_dealloc(cd);
 
     PyBuffer_Release(view);
@@ -2043,6 +2044,7 @@ static void cdatagcp_dealloc(CDataObject_gcp *cd)
 {
     PyObject *destructor = cd->destructor;
     PyObject *origobj = cd->origobj;
+    PyObject_GC_UnTrack(cd);
     cdata_dealloc((CDataObject *)cd);
 
     gcp_finalize(destructor, origobj);

testing/cffi0/test_ffi_backend.py

@@ -159,6 +159,24 @@ def test_bogus_struct_containing_struct_containing_array_varsize(self):
         assert p.bcd == 9999999
         assert p.foo.data[3] != 78   # has been overwritten with 9999999
 
+    def test_issue553(self):
+        import gc, warnings
+        ffi = FFI(backend=self.Backend())
+        p = ffi.new("int *", 123)
+        with warnings.catch_warnings(record=True) as w:
+            ffi.gc(p, lambda x: None)
+            gc.collect()
+        assert w == []
+
+    def test_issue553_from_buffer(self):
+        import gc, warnings
+        ffi = FFI(backend=self.Backend())
+        buf = b"123"
+        with warnings.catch_warnings(record=True) as w:
+            ffi.from_buffer(buf)
+            gc.collect()
+        assert w == []
+
 
 class TestBitfield:
     def check(self, source, expected_ofs_y, expected_align, expected_size):