Fix case where absolute nodes would sometimes not be cloned (#1675)

Summary:
X-link: facebook/react-native#45240

Pull Request resolved: #1675

There was a bug where some crash would happen if a tree was cloned that had static/absolute parent/child pair inside it. This was because we were no longer calling `cloneChildrenIfNeeded` on the static parent, but would still layout the absolute child. So that child's owner would be stale and have new layout. In React Native this would lead to a failed assert which causes the crash.

The fix here is to clone the children of static nodes during `layoutAbsoluteDescendants` so that we guarantee the node is either cloned if it is going to have new layout.

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D59175629

tests/YGCloneNodeTest.cpp

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <gtest/gtest.h>
+#include <yoga/Yoga.h>
+
+static void recursivelyAssertProperNodeOwnership(YGNodeRef node) {
+  for (size_t i = 0; i < YGNodeGetChildCount(node); ++i) {
+    const auto child = YGNodeGetChild(node, i);
+    ASSERT_EQ(node, YGNodeGetOwner(child));
+    recursivelyAssertProperNodeOwnership(child);
+  }
+}
+
+TEST(YogaTest, absolute_node_cloned_with_static_parent) {
+  YGNodeRef root = YGNodeNew();
+  YGNodeStyleSetWidth(root, 100);
+  YGNodeStyleSetHeight(root, 100);
+
+  YGNodeRef root_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(root_child0, YGPositionTypeStatic);
+  YGNodeStyleSetWidth(root_child0, 10);
+  YGNodeStyleSetHeight(root_child0, 10);
+  YGNodeInsertChild(root, root_child0, 0);
+
+  YGNodeRef root_child0_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(root_child0_child0, YGPositionTypeAbsolute);
+  YGNodeStyleSetWidthPercent(root_child0_child0, 1);
+  YGNodeStyleSetHeight(root_child0_child0, 1);
+  YGNodeInsertChild(root_child0, root_child0_child0, 0);
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  YGNodeRef clonedRoot = YGNodeClone(root);
+  YGNodeStyleSetWidth(clonedRoot, 110);
+  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);
+  YGNodeStyleSetHeight(root, 100);
+
+  YGNodeRef root_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(root_child0, YGPositionTypeStatic);
+  YGNodeStyleSetWidth(root_child0, 50);
+  YGNodeStyleSetHeight(root_child0, 50);
+  YGNodeInsertChild(root, root_child0, 0);
+
+  YGNodeRef root_child0_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(root_child0_child0, YGPositionTypeStatic);
+  YGNodeStyleSetWidth(root_child0_child0, 40);
+  YGNodeStyleSetHeight(root_child0_child0, 40);
+  YGNodeInsertChild(root_child0, root_child0_child0, 0);
+
+  YGNodeRef root_child0_child0_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(root_child0_child0_child0, YGPositionTypeStatic);
+  YGNodeStyleSetWidth(root_child0_child0_child0, 30);
+  YGNodeStyleSetHeight(root_child0_child0_child0, 30);
+  YGNodeInsertChild(root_child0_child0, root_child0_child0_child0, 0);
+
+  YGNodeRef root_child0_child0_child0_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(
+      root_child0_child0_child0_child0, YGPositionTypeAbsolute);
+  YGNodeStyleSetWidthPercent(root_child0_child0_child0_child0, 1);
+  YGNodeStyleSetHeight(root_child0_child0_child0_child0, 1);
+  YGNodeInsertChild(
+      root_child0_child0_child0, root_child0_child0_child0_child0, 0);
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  YGNodeRef clonedRoot = YGNodeClone(root);
+  YGNodeStyleSetWidth(clonedRoot, 110);
+  YGNodeCalculateLayout(clonedRoot, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  recursivelyAssertProperNodeOwnership(clonedRoot);
+
+  YGNodeFreeRecursive(root);
+  YGNodeFreeRecursive(clonedRoot);
+}

tests/YGRelayoutTest.cpp

@@ -207,3 +207,43 @@ TEST(YogaTest, relayout_containing_block_size_changes) {
 
   YGConfigFree(config);
 }
+
+TEST(YogaTest, has_new_layout_flag_set_static) {
+  YGNodeRef root = YGNodeNew();
+  YGNodeStyleSetWidth(root, 100);
+  YGNodeStyleSetHeight(root, 100);
+
+  YGNodeRef root_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(root_child0, YGPositionTypeStatic);
+  YGNodeStyleSetWidth(root_child0, 10);
+  YGNodeStyleSetHeight(root_child0, 10);
+  YGNodeInsertChild(root, root_child0, 0);
+
+  YGNodeRef root_child0_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(root_child0_child0, YGPositionTypeStatic);
+  YGNodeStyleSetWidth(root_child0_child0, 5);
+  YGNodeStyleSetHeight(root_child0_child0, 5);
+  YGNodeInsertChild(root_child0, root_child0_child0, 0);
+
+  YGNodeRef root_child0_child0_child0 = YGNodeNew();
+  YGNodeStyleSetPositionType(root_child0_child0_child0, YGPositionTypeAbsolute);
+  YGNodeStyleSetWidthPercent(root_child0_child0_child0, 1);
+  YGNodeStyleSetHeight(root_child0_child0_child0, 1);
+  YGNodeInsertChild(root_child0_child0, root_child0_child0_child0, 0);
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+  YGNodeSetHasNewLayout(root, false);
+  YGNodeSetHasNewLayout(root_child0, false);
+  YGNodeSetHasNewLayout(root_child0_child0, false);
+  YGNodeSetHasNewLayout(root_child0_child0_child0, false);
+
+  YGNodeStyleSetWidth(root, 110);
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  ASSERT_TRUE(YGNodeGetHasNewLayout(root));
+  ASSERT_TRUE(YGNodeGetHasNewLayout(root_child0));
+  ASSERT_TRUE(YGNodeGetHasNewLayout(root_child0_child0));
+  ASSERT_TRUE(YGNodeGetHasNewLayout(root_child0_child0_child0));
+
+  YGNodeFreeRecursive(root);
+}

yoga/algorithm/AbsoluteLayout.cpp

@@ -474,7 +474,7 @@ void layoutAbsoluteChild(
       containingBlockHeight);
 }
 
-void layoutAbsoluteDescendants(
+bool layoutAbsoluteDescendants(
     yoga::Node* containingNode,
     yoga::Node* currentNode,
     SizingMode widthSizingMode,
@@ -486,6 +486,7 @@ void layoutAbsoluteDescendants(
     float currentNodeTopOffsetFromContainingBlock,
     float containingNodeAvailableInnerWidth,
     float containingNodeAvailableInnerHeight) {
+  bool hasNewLayout = false;
   for (auto child : currentNode->getChildren()) {
     if (child->style().display() == Display::None) {
       continue;
@@ -514,6 +515,8 @@ void layoutAbsoluteDescendants(
           currentDepth,
           generationCount);
 
+      hasNewLayout = hasNewLayout || child->getHasNewLayout();
+
       /*
        * At this point the child has its position set but only on its the
        * parent's flexStart edge. Additionally, this position should be
@@ -571,6 +574,13 @@ void layoutAbsoluteDescendants(
     } else if (
         child->style().positionType() == PositionType::Static &&
         !child->alwaysFormsContainingBlock()) {
+      // We may write new layout results for absolute descendants of "child"
+      // which are positioned relative to the current containing block instead
+      // of their parent. "child" may not be dirty, or have new constraints, so
+      // absolute positioning may be the first time during this layout pass that
+      // we need to mutate these descendents. Make sure the path of
+      // nodes to them is mutable before positioning.
+      child->cloneChildrenIfNeeded();
       const Direction childDirection =
           child->resolveDirection(currentNodeDirection);
       // By now all descendants of the containing block that are not absolute
@@ -582,19 +592,25 @@ void layoutAbsoluteDescendants(
           currentNodeTopOffsetFromContainingBlock +
           child->getLayout().position(PhysicalEdge::Top);
 
-      layoutAbsoluteDescendants(
-          containingNode,
-          child,
-          widthSizingMode,
-          childDirection,
-          layoutMarkerData,
-          currentDepth + 1,
-          generationCount,
-          childLeftOffsetFromContainingBlock,
-          childTopOffsetFromContainingBlock,
-          containingNodeAvailableInnerWidth,
-          containingNodeAvailableInnerHeight);
+      hasNewLayout = hasNewLayout ||
+          layoutAbsoluteDescendants(
+                         containingNode,
+                         child,
+                         widthSizingMode,
+                         childDirection,
+                         layoutMarkerData,
+                         currentDepth + 1,
+                         generationCount,
+                         childLeftOffsetFromContainingBlock,
+                         childTopOffsetFromContainingBlock,
+                         containingNodeAvailableInnerWidth,
+                         containingNodeAvailableInnerHeight);
+
+      if (hasNewLayout) {
+        child->setHasNewLayout(hasNewLayout);
+      }
     }
   }
+  return hasNewLayout;
 }
 } // namespace facebook::yoga

yoga/algorithm/AbsoluteLayout.h

@@ -24,7 +24,8 @@ void layoutAbsoluteChild(
     uint32_t depth,
     uint32_t generationCount);
 
-void layoutAbsoluteDescendants(
+// Returns if some absolute descendant has new layout
+bool layoutAbsoluteDescendants(
     yoga::Node* containingNode,
     yoga::Node* currentNode,
     SizingMode widthSizingMode,