Fix node ownership when display: contents is used (#1924)

tests/YGCloneNodeTest.cpp

@@ -45,6 +45,48 @@ TEST(YogaTest, absolute_node_cloned_with_static_parent) {
   YGNodeFreeRecursive(clonedRoot);
 }
 
+TEST(YogaTest, absolute_node_cloned_through_nested_display_contents) {
+  YGNodeRef root = YGNodeNew();
+  YGNodeStyleSetWidth(root, 100);
+  YGNodeStyleSetHeight(root, 100);
+
+  YGNodeRef wrapper = YGNodeNew();
+  YGNodeStyleSetPositionType(wrapper, YGPositionTypeStatic);
+  YGNodeStyleSetWidth(wrapper, 50);
+  YGNodeStyleSetHeight(wrapper, 50);
+  YGNodeInsertChild(root, wrapper, 0);
+
+  YGNodeRef static1 = YGNodeNew();
+  YGNodeStyleSetPositionType(static1, YGPositionTypeStatic);
+  YGNodeStyleSetFlexGrow(static1, 1);
+  YGNodeInsertChild(wrapper, static1, 0);
+
+  YGNodeRef contents1 = YGNodeNew();
+  YGNodeStyleSetDisplay(contents1, YGDisplayContents);
+  YGNodeInsertChild(static1, contents1, 0);
+
+  YGNodeRef contents2 = YGNodeNew();
+  YGNodeStyleSetDisplay(contents2, YGDisplayContents);
+  YGNodeInsertChild(contents1, contents2, 0);
+
+  YGNodeRef absolute = YGNodeNew();
+  YGNodeStyleSetPositionType(absolute, YGPositionTypeAbsolute);
+  YGNodeStyleSetWidthPercent(absolute, 50);
+  YGNodeStyleSetHeight(absolute, 1);
+  YGNodeInsertChild(contents2, absolute, 0);
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  YGNodeRef clonedRoot = YGNodeClone(root);
+  YGNodeStyleSetWidth(clonedRoot, 200);
+  YGNodeCalculateLayout(clonedRoot, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  recursivelyAssertProperNodeOwnership(clonedRoot);
+
+  YGNodeFreeRecursive(root);
+  YGNodeFreeRecursive(clonedRoot);
+}
+
 TEST(YogaTest, absolute_node_cloned_with_static_ancestors) {
   YGNodeRef root = YGNodeNew();
   YGNodeStyleSetWidth(root, 100);

yoga/algorithm/AbsoluteLayout.cpp

@@ -558,6 +558,7 @@ bool layoutAbsoluteDescendants(
       // we need to mutate these descendents. Make sure the path of
       // nodes to them is mutable before positioning.
       child->cloneChildrenIfNeeded();
+      cleanupContentsNodesRecursively(child);
       const Direction childDirection =
           child->resolveDirection(currentNodeDirection);
       // By now all descendants of the containing block that are not absolute

yoga/node/Node.cpp

@@ -392,7 +392,12 @@ void Node::cloneChildrenIfNeeded() {
       child = resolveRef(config_->cloneNode(child, this, i));
       child->setOwner(this);
 
-      if (child->hasContentsChildren()) [[unlikely]] {
+      if (child->style().display() == Display::Contents) [[unlikely]] {
+        // The contents node's children are treated as children of the
+        // contents node's parent for layout purposes, so they need
+        // to be cloned as well.
+        child->cloneChildrenIfNeeded();
+      } else if (child->hasContentsChildren()) [[unlikely]] {
         child->cloneContentsChildrenIfNeeded();
       }
     }