From d04b1e5a16c07e1d7e3225ea42230a8905f92708 Mon Sep 17 00:00:00 2001
From: Andrew Coates <30809111+acoates-ms@users.noreply.github.com>
Date: Tue, 18 Jun 2024 11:52:27 -0700
Subject: [PATCH] Ensure full layout occurs when a system scale change occurs

---
 .../react/renderer/components/root/RootShadowNode.cpp         | 4 +++-
 .../ReactCommon/yoga/yoga/algorithm/CalculateLayout.cpp       | 4 +++-
 .../react-native/ReactCommon/yoga/yoga/node/LayoutResults.cpp | 1 +
 .../react-native/ReactCommon/yoga/yoga/node/LayoutResults.h   | 1 +
 4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/packages/react-native/ReactCommon/react/renderer/components/root/RootShadowNode.cpp b/packages/react-native/ReactCommon/react/renderer/components/root/RootShadowNode.cpp
index 015366dacc8466..55fe705dec1388 100644
--- a/packages/react-native/ReactCommon/react/renderer/components/root/RootShadowNode.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/components/root/RootShadowNode.cpp
@@ -49,7 +49,9 @@ RootShadowNode::Unshared RootShadowNode::clone(
           /* .props = */ props,
       });
 
-  if (layoutConstraints != getConcreteProps().layoutConstraints) {
+  if (layoutConstraints != getConcreteProps().layoutConstraints ||
+      layoutContext.pointScaleFactor !=
+          getConcreteProps().layoutContext.pointScaleFactor) {
     newRootShadowNode->dirtyLayout();
   }
 
diff --git a/packages/react-native/ReactCommon/yoga/yoga/algorithm/CalculateLayout.cpp b/packages/react-native/ReactCommon/yoga/yoga/algorithm/CalculateLayout.cpp
index 58394a4563210b..74c634ab36964b 100644
--- a/packages/react-native/ReactCommon/yoga/yoga/algorithm/CalculateLayout.cpp
+++ b/packages/react-native/ReactCommon/yoga/yoga/algorithm/CalculateLayout.cpp
@@ -2140,7 +2140,8 @@ bool calculateLayoutInternal(
 
   const bool needToVisitNode =
       (node->isDirty() && layout->generationCount != generationCount) ||
-      layout->lastOwnerDirection != ownerDirection;
+      layout->lastOwnerDirection != ownerDirection ||
+      layout->lastScale != node->getConfig()->getPointScaleFactor();
 
   if (needToVisitNode) {
     // Invalidate the cached results.
@@ -2255,6 +2256,7 @@ bool calculateLayoutInternal(
         reason);
 
     layout->lastOwnerDirection = ownerDirection;
+    layout->lastScale = node->getConfig()->getPointScaleFactor();
 
     if (cachedResults == nullptr) {
       layoutMarkerData.maxMeasureCache = std::max(
diff --git a/packages/react-native/ReactCommon/yoga/yoga/node/LayoutResults.cpp b/packages/react-native/ReactCommon/yoga/yoga/node/LayoutResults.cpp
index fd70870e65b3a7..d1a8ecc78b5fcf 100644
--- a/packages/react-native/ReactCommon/yoga/yoga/node/LayoutResults.cpp
+++ b/packages/react-native/ReactCommon/yoga/yoga/node/LayoutResults.cpp
@@ -21,6 +21,7 @@ bool LayoutResults::operator==(LayoutResults layout) const {
       direction() == layout.direction() &&
       hadOverflow() == layout.hadOverflow() &&
       lastOwnerDirection == layout.lastOwnerDirection &&
+      lastScale == layout.lastScale &&
       nextCachedMeasurementsIndex == layout.nextCachedMeasurementsIndex &&
       cachedLayout == layout.cachedLayout &&
       computedFlexBasis == layout.computedFlexBasis;
diff --git a/packages/react-native/ReactCommon/yoga/yoga/node/LayoutResults.h b/packages/react-native/ReactCommon/yoga/yoga/node/LayoutResults.h
index f42c27795c107d..bec3d1293d4661 100644
--- a/packages/react-native/ReactCommon/yoga/yoga/node/LayoutResults.h
+++ b/packages/react-native/ReactCommon/yoga/yoga/node/LayoutResults.h
@@ -31,6 +31,7 @@ struct LayoutResults {
   // information to break early when nothing changed
   uint32_t generationCount = 0;
   Direction lastOwnerDirection = Direction::Inherit;
+  float lastScale = 1.0f;
 
   uint32_t nextCachedMeasurementsIndex = 0;
   std::array<CachedMeasurement, MaxCachedMeasurements> cachedMeasurements = {};