From a1954c8935118e8e98c0af7a79cb1e028bd23a94 Mon Sep 17 00:00:00 2001
From: kwy404 <thekaway404@gmail.com>
Date: Fri, 25 Sep 2026 16:17:23 -0300
Subject: [PATCH] Fix stale layout when a child switches to display: contents
 after insertion

Each node caches how many of its children use `display: contents`, but
the count is only updated when children are inserted, removed or
replaced. Setting `display: contents` on a child that is already
attached left the count at zero, so the owner skipped
`cleanupContentsNodesRecursively` and the contents node stayed dirty
after layout. Dirty marking from its children then stopped at that node
and never reached the root, so later style changes were ignored.

Recompute the owner's count in `YGNodeStyleSetDisplay` when a node with
an owner switches to or from `display: contents`.
---
 tests/YGDirtyMarkingTest.cpp | 26 ++++++++++++++++++++++++++
 yoga/YGNodeStyle.cpp         |  9 +++++++++
 2 files changed, 35 insertions(+)

diff --git a/tests/YGDirtyMarkingTest.cpp b/tests/YGDirtyMarkingTest.cpp
index 9e098a4561..f0d22312ee 100644
--- a/tests/YGDirtyMarkingTest.cpp
+++ b/tests/YGDirtyMarkingTest.cpp
@@ -339,3 +339,29 @@ TEST(YogaTest, dirty_parent_when_subtree_freed_recursive) {
   EXPECT_TRUE(YGNodeIsDirty(root));
   YGNodeFree(root);
 }
+
+TEST(YogaTest, dirty_propagation_through_child_set_to_display_contents) {
+  YGNodeRef root = YGNodeNew();
+  YGNodeStyleSetWidth(root, 100);
+  YGNodeStyleSetHeight(root, 100);
+
+  YGNodeRef child = YGNodeNew();
+  YGNodeInsertChild(root, child, 0);
+
+  YGNodeRef grandchild = YGNodeNew();
+  YGNodeStyleSetWidth(grandchild, 10);
+  YGNodeStyleSetHeight(grandchild, 10);
+  YGNodeInsertChild(child, grandchild, 0);
+
+  YGNodeStyleSetDisplay(child, YGDisplayContents);
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+  EXPECT_FALSE(YGNodeIsDirty(child));
+
+  YGNodeStyleSetWidth(grandchild, 20);
+  EXPECT_TRUE(YGNodeIsDirty(root));
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+  ASSERT_FLOAT_EQ(20, YGNodeLayoutGetWidth(grandchild));
+
+  YGNodeFreeRecursive(root);
+}
diff --git a/yoga/YGNodeStyle.cpp b/yoga/YGNodeStyle.cpp
index e43a38e64e..86da8ddf20 100644
--- a/yoga/YGNodeStyle.cpp
+++ b/yoga/YGNodeStyle.cpp
@@ -152,7 +152,16 @@ YGOverflow YGNodeStyleGetOverflow(const YGNodeConstRef node) {
 }
 
 void YGNodeStyleSetDisplay(const YGNodeRef node, const YGDisplay display) {
+  const bool wasContents =
+      resolveRef(node)->style().display() == Display::Contents;
   updateStyle<&Style::display, &Style::setDisplay>(node, scopedEnum(display));
+
+  // The owner caches how many of its children use display: contents, so it
+  // has to be recomputed when an attached child switches to or from it.
+  auto owner = resolveRef(node)->getOwner();
+  if (owner != nullptr && wasContents != (display == YGDisplayContents)) {
+    owner->setChildren(owner->getChildren());
+  }
 }
 
 YGDisplay YGNodeStyleGetDisplay(const YGNodeConstRef node) {