Reset currentEventTransitionLane after flushing sync work

sebmarkbage · sebmarkbage · commit b10e38dba5d3 · 2025-05-08T21:37:44.000-04:00
diff --git a/packages/react-reconciler/src/ReactFiberRootScheduler.js b/packages/react-reconciler/src/ReactFiberRootScheduler.js
@@ -257,7 +257,6 @@ function processRootScheduleInMicrotask() {
       // preserve the scroll position of the previous page.
       syncTransitionLanes = currentEventTransitionLane;
     }
-    currentEventTransitionLane = NoLane;
   }
 
   const currentTime = now();
@@ -315,6 +314,9 @@ function processRootScheduleInMicrotask() {
   if (!hasPendingCommitEffects()) {
     flushSyncWorkAcrossRoots_impl(syncTransitionLanes, false);
   }
+
+  // Reset Event Transition Lane so that we allocate a new one next time.
+  currentEventTransitionLane = NoLane;
 }
 
 function scheduleTaskForRootDuringMicrotask(

Original file line number	Diff line number	Diff line change
`@@ -257,7 +257,6 @@ function processRootScheduleInMicrotask() {`
`257`	`257`	`// preserve the scroll position of the previous page.`
`258`	`258`	`syncTransitionLanes = currentEventTransitionLane;`
`259`	`259`	`}`
`260`		`- currentEventTransitionLane = NoLane;`
`261`	`260`	`}`
`262`	`261`
`263`	`262`	`const currentTime = now();`
`@@ -315,6 +314,9 @@ function processRootScheduleInMicrotask() {`
`315`	`314`	`if (!hasPendingCommitEffects()) {`
`316`	`315`	`flushSyncWorkAcrossRoots_impl(syncTransitionLanes, false);`
`317`	`316`	`}`
	`317`	`+`
	`318`	`+ // Reset Event Transition Lane so that we allocate a new one next time.`
	`319`	`+ currentEventTransitionLane = NoLane;`
`318`	`320`	`}`
`319`	`321`
`320`	`322`	`function scheduleTaskForRootDuringMicrotask(`