Merge pull request #91799 from callstack-internal/VickyStash/bugfix/91584-flashlist-web-subpixel-loop

Author: mountiny

patches/@shopify/flash-list/@shopify+flash-list+2.3.0+010+fix-web-subpixel-rounding.patch

@@ -0,0 +1,16 @@
+diff --git a/node_modules/@shopify/flash-list/dist/recyclerview/utils/measureLayout.web.js b/node_modules/@shopify/flash-list/dist/recyclerview/utils/measureLayout.web.js
+index 17d9812..fe112f1 100644
+--- a/node_modules/@shopify/flash-list/dist/recyclerview/utils/measureLayout.web.js
++++ b/node_modules/@shopify/flash-list/dist/recyclerview/utils/measureLayout.web.js
+@@ -28,7 +28,10 @@ export function areDimensionsEqual(value1, value2) {
+     return Math.abs(value1 - value2) <= 1;
+ }
+ export function roundOffPixel(value) {
+-    return value;
++    const dpr = typeof window !== "undefined" && window.devicePixelRatio
++        ? window.devicePixelRatio
++        : 1;
++    return Math.round(value * dpr) / dpr;
+ }
+ /**
+  * Measures the size of the RecyclerView's outer container.

patches/@shopify/flash-list/details.md

@@ -74,3 +74,12 @@
 - Upstream PR/issue: https://github.com/Shopify/flash-list/issues/2291
 - E/App issue: https://github.com/Expensify/App/issues/89933
 - PR introducing patch: https://github.com/Expensify/App/pull/91248
+
+### [@shopify+flash-list+2.3.0+010+fix-web-subpixel-rounding.patch](@shopify+flash-list+2.3.0+010+fix-web-subpixel-rounding.patch)
+
+- Reason: Fixes a "Maximum update depth exceeded" infinite render loop on web (mostly Windows with fractional display scaling). `roundOffPixel` on web was a no-op, so subpixel drift in the child container's `getBoundingClientRect()` width re-triggered `ViewHolderCollection`'s `[fixedContainerSize]` layout effect on every measurement. The patch implements `roundOffPixel` to snap to the device-pixel grid (`Math.round(value * devicePixelRatio) / devicePixelRatio`), matching native `PixelRatio.roundToNearestPixel`. Two measurements that paint the same physical pixel now collapse to the same JS value, breaking the loop.
+- Files changed: `dist/recyclerview/utils/measureLayout.web.js` only.
+- Upstream PR/issue: TBD
+- E/App issue: https://github.com/Expensify/App/issues/91584
+- Sentry: https://expensify.sentry.io/issues/APP-DQ2
+- PR introducing patch: https://github.com/Expensify/App/pull/91799