remove versioning

Author: picnixz

Modules/_elementtree.c

@@ -229,9 +229,6 @@ typedef struct {
     PyObject* *children;
 
     PyObject* _children[STATIC_CHILDREN];
-
-    /* incremented whenever the object is externally mutated */
-    size_t version;
 } ElementObjectExtra;
 
 typedef struct {
@@ -281,8 +278,6 @@ create_extra(ElementObject* self, PyObject* attrib)
     self->extra->allocated = STATIC_CHILDREN;
     self->extra->children = self->extra->_children;
 
-    self->extra->version = 0;
-
     return 0;
 }
 
@@ -510,7 +505,6 @@ element_resize(ElementObject* self, Py_ssize_t extra)
         }
         self->extra->children = children;
         self->extra->allocated = size;
-        self->extra->version++;
     }
 
     return 0;
@@ -544,7 +538,6 @@ element_add_subelement(elementtreestate *st, ElementObject *self,
     self->extra->children[self->extra->length] = Py_NewRef(element);
 
     self->extra->length++;
-    self->extra->version++;
 
     return 0;
 }
@@ -786,7 +779,6 @@ _elementtree_Element___copy___impl(ElementObject *self, PyTypeObject *cls)
 
         assert(!element->extra->length);
         element->extra->length = self->extra->length;
-        element->extra->version = self->extra->version;
     }
 
     return (PyObject*) element;
@@ -870,7 +862,6 @@ _elementtree_Element___deepcopy___impl(ElementObject *self, PyObject *memo)
 
         assert(!element->extra->length);
         element->extra->length = self->extra->length;
-        element->extra->version = 0;
     }
 
     /* add object to memo dictionary (so deepcopy won't visit it again) */
@@ -1557,7 +1548,6 @@ _elementtree_Element_insert_impl(ElementObject *self, Py_ssize_t index,
     self->extra->children[index] = Py_NewRef(subelement);
 
     self->extra->length++;
-    self->extra->version++;
 
     Py_RETURN_NONE;
 }
@@ -1648,17 +1638,17 @@ _elementtree_Element_remove_impl(ElementObject *self, PyObject *subelement)
     }
 
     Py_ssize_t i;
-    size_t old_version = self->extra->version;
+    const Py_ssize_t length = self->extra->length;
     for (i = 0; self->extra && i < self->extra->length; i++) {
-        if (old_version != self->extra->version) {
-            goto fail;
-        }
-        else if (self->extra->children[i] == subelement) {
+        if (self->extra->children[i] == subelement) {
             break;
         }
         PyObject *child = Py_NewRef(self->extra->children[i]);
         int rc = PyObject_RichCompareBool(child, subelement, Py_EQ);
         Py_DECREF(child);
+        if (self->extra ==  NULL || self->extra->length != length) {
+            goto fail;
+        }
         if (rc > 0) {
             break;
         }
@@ -1667,8 +1657,10 @@ _elementtree_Element_remove_impl(ElementObject *self, PyObject *subelement)
         }
     }
 
-    // An extra check must be done if the mutation occurs at the very last step.
-    if (self->extra == NULL || old_version != self->extra->version) {
+    // An extra check must be done if the mutation occurs at the very last
+    // step and removes or clears the 'extra' list (the condition on the
+    // length would not be satisfied any more).
+    if (self->extra == NULL || self->extra->length != length) {
         goto fail;
     }
     else if (i >= self->extra->length) {
@@ -1682,7 +1674,6 @@ _elementtree_Element_remove_impl(ElementObject *self, PyObject *subelement)
     for (; i < self->extra->length; i++) {
         self->extra->children[i] = self->extra->children[i+1];
     }
-    self->extra->version++;
 
     Py_DECREF(found);
     Py_RETURN_NONE;
@@ -1746,7 +1737,6 @@ _elementtree_Element_set_impl(ElementObject *self, PyObject *key,
     if (PyDict_SetItem(attrib, key, value) < 0)
         return NULL;
 
-    self->extra->version++;
     Py_RETURN_NONE;
 }
 
@@ -1780,7 +1770,6 @@ element_setitem(PyObject* self_, Py_ssize_t index, PyObject* item)
             self->extra->children[i] = self->extra->children[i+1];
     }
 
-    self->extra->version++;
     Py_DECREF(old);
 
     return 0;
@@ -1931,7 +1920,6 @@ element_ass_subscr(PyObject* self_, PyObject* item, PyObject* value)
             }
 
             self->extra->length -= slicelen;
-            self->extra->version++;
 
             /* Discard the recycle list with all the deleted sub-elements */
             Py_DECREF(recycle);
@@ -2007,7 +1995,6 @@ element_ass_subscr(PyObject* self_, PyObject* item, PyObject* value)
         }
 
         self->extra->length += newlen - slicelen;
-        self->extra->version++;
 
         Py_DECREF(seq);
 
@@ -2104,7 +2091,6 @@ element_attrib_setter(ElementObject *self, PyObject *value, void *closure)
             return -1;
     }
     Py_XSETREF(self->extra->attrib, Py_NewRef(value));
-    self->extra->version++;
     return 0;
 }