commit 97bbdb28b4ab9519780f924e3267ac70af1cd5b8
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Mon Mar 09 05:55:17 2020 -0700
committer GitHub <noreply@github.com> Mon Mar 09 05:55:17 2020 -0700
tree 641c9e71a7ed63cfb19f39cc7b17886fd4ea45f8
parent f3f0c7a108cd2a5071592e77e2f4b14ca35d4fcc

bpo-39903: Fix double decref in _elementtree.Element.__getstate__ (GH-18850)

(cherry picked from commit 88944a44aa84b0f3674939019b1befbc7a9dc874)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Modules/_elementtree.c

diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index c3f30c9..776b86c 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -950,8 +950,8 @@
 _elementtree_Element___getstate___impl(ElementObject *self)
 /*[clinic end generated code: output=37279aeeb6bb5b04 input=f0d16d7ec2f7adc1]*/
 {
-    Py_ssize_t i, noattrib;
-    PyObject *instancedict = NULL, *children;
+    Py_ssize_t i;
+    PyObject *children, *attrib;
 
     /* Build a list of children. */
     children = PyList_New(self->extra ? self->extra->length : 0);
@@ -963,33 +963,24 @@
         PyList_SET_ITEM(children, i, child);
     }
 
-    /* Construct the state object. */
-    noattrib = (self->extra == NULL || self->extra->attrib == Py_None);
-    if (noattrib)
-        instancedict = Py_BuildValue("{sOsOs{}sOsO}",
-                                     PICKLED_TAG, self->tag,
-                                     PICKLED_CHILDREN, children,
-                                     PICKLED_ATTRIB,
-                                     PICKLED_TEXT, JOIN_OBJ(self->text),
-                                     PICKLED_TAIL, JOIN_OBJ(self->tail));
-    else
-        instancedict = Py_BuildValue("{sOsOsOsOsO}",
-                                     PICKLED_TAG, self->tag,
-                                     PICKLED_CHILDREN, children,
-                                     PICKLED_ATTRIB, self->extra->attrib,
-                                     PICKLED_TEXT, JOIN_OBJ(self->text),
-                                     PICKLED_TAIL, JOIN_OBJ(self->tail));
-    if (instancedict) {
-        Py_DECREF(children);
-        return instancedict;
+    if (self->extra && self->extra->attrib != Py_None) {
+        attrib = self->extra->attrib;
+        Py_INCREF(attrib);
     }
     else {
-        for (i = 0; i < PyList_GET_SIZE(children); i++)
-            Py_DECREF(PyList_GET_ITEM(children, i));
-        Py_DECREF(children);
-
-        return NULL;
+        attrib = PyDict_New();
+        if (!attrib) {
+            Py_DECREF(children);
+            return NULL;
+        }
     }
+
+    return Py_BuildValue("{sOsNsNsOsO}",
+                         PICKLED_TAG, self->tag,
+                         PICKLED_CHILDREN, children,
+                         PICKLED_ATTRIB, attrib,
+                         PICKLED_TEXT, JOIN_OBJ(self->text),
+                         PICKLED_TAIL, JOIN_OBJ(self->tail));
 }
 
 static PyObject *