Reset currentEventTransitionLane after flushing sync work (#33159)

This keeps track of the transition lane allocated for this event. I want
to be able to use the current one within sync work flushing to know
which lane needs its loading indicator cleared.

It's also a bit weird that transition work scheduled inside sync updates
in the same event aren't entangled with other transitions in that event
when `flushSync` is.

Therefore this moves it to reset after flushing.

It should have no impact. Just splitting it out into a separate PR for
an abundance of caution.

The only thing this might affect would be if the React internals throws
and it doesn't reset after. But really it doesn't really have to reset
and they're all entangled anyway.

DiffTrain build for [676f087](676f087)

Author: sebmarkbage

compiled/facebook-www/REVISION

@@ -1 +1 @@
-0cac32d60dd4482b27fe8a54dffbabceb22c6272
+676f0879f315130309262ff3532707029f0288bb

compiled/facebook-www/REVISION_TRANSFORMS

@@ -1 +1 @@
-0cac32d60dd4482b27fe8a54dffbabceb22c6272
+676f0879f315130309262ff3532707029f0288bb

compiled/facebook-www/React-dev.classic.js

@@ -1537,7 +1537,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.2.0-www-classic-0cac32d6-20250513";
+    exports.version = "19.2.0-www-classic-676f0879-20250513";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-dev.modern.js

@@ -1537,7 +1537,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.2.0-www-modern-0cac32d6-20250513";
+    exports.version = "19.2.0-www-modern-676f0879-20250513";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-prod.classic.js

@@ -635,4 +635,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-classic-0cac32d6-20250513";
+exports.version = "19.2.0-www-classic-676f0879-20250513";

compiled/facebook-www/React-prod.modern.js

@@ -635,4 +635,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-modern-0cac32d6-20250513";
+exports.version = "19.2.0-www-modern-676f0879-20250513";

compiled/facebook-www/React-profiling.classic.js

@@ -639,7 +639,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-classic-0cac32d6-20250513";
+exports.version = "19.2.0-www-classic-676f0879-20250513";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-profiling.modern.js

@@ -639,7 +639,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-modern-0cac32d6-20250513";
+exports.version = "19.2.0-www-modern-676f0879-20250513";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/ReactART-dev.classic.js

@@ -2971,11 +2971,8 @@ __DEV__ &&
       scheduleCallback$3(ImmediatePriority, processRootScheduleInImmediateTask);
     }
     function requestTransitionLane() {
-      if (0 === currentEventTransitionLane) {
-        var actionScopeLane = currentEntangledLane;
-        currentEventTransitionLane =
-          0 !== actionScopeLane ? actionScopeLane : claimNextTransitionLane();
-      }
+      0 === currentEventTransitionLane &&
+        (currentEventTransitionLane = claimNextTransitionLane());
       return currentEventTransitionLane;
     }
     function entangleAsyncAction(transition, thenable) {
@@ -13914,7 +13911,8 @@ __DEV__ &&
       return null !== transition
         ? (transition._updatedFibers || (transition._updatedFibers = new Set()),
           transition._updatedFibers.add(fiber),
-          requestTransitionLane())
+          (fiber = currentEntangledLane),
+          0 !== fiber ? fiber : requestTransitionLane())
         : currentUpdatePriority || DefaultEventPriority;
     }
     function requestDeferredLane() {
@@ -19067,10 +19065,10 @@ __DEV__ &&
     (function () {
       var internals = {
         bundleType: 1,
-        version: "19.2.0-www-classic-0cac32d6-20250513",
+        version: "19.2.0-www-classic-676f0879-20250513",
         rendererPackageName: "react-art",
         currentDispatcherRef: ReactSharedInternals,
-        reconcilerVersion: "19.2.0-www-classic-0cac32d6-20250513"
+        reconcilerVersion: "19.2.0-www-classic-676f0879-20250513"
       };
       internals.overrideHookState = overrideHookState;
       internals.overrideHookStateDeletePath = overrideHookStateDeletePath;
@@ -19104,7 +19102,7 @@ __DEV__ &&
     exports.Shape = Shape;
     exports.Surface = Surface;
     exports.Text = Text;
-    exports.version = "19.2.0-www-classic-0cac32d6-20250513";
+    exports.version = "19.2.0-www-classic-676f0879-20250513";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/ReactART-dev.modern.js

@@ -2877,11 +2877,8 @@ __DEV__ &&
       scheduleCallback$3(ImmediatePriority, processRootScheduleInImmediateTask);
     }
     function requestTransitionLane() {
-      if (0 === currentEventTransitionLane) {
-        var actionScopeLane = currentEntangledLane;
-        currentEventTransitionLane =
-          0 !== actionScopeLane ? actionScopeLane : claimNextTransitionLane();
-      }
+      0 === currentEventTransitionLane &&
+        (currentEventTransitionLane = claimNextTransitionLane());
       return currentEventTransitionLane;
     }
     function entangleAsyncAction(transition, thenable) {
@@ -13732,7 +13729,8 @@ __DEV__ &&
       return null !== transition
         ? (transition._updatedFibers || (transition._updatedFibers = new Set()),
           transition._updatedFibers.add(fiber),
-          requestTransitionLane())
+          (fiber = currentEntangledLane),
+          0 !== fiber ? fiber : requestTransitionLane())
         : currentUpdatePriority || DefaultEventPriority;
     }
     function requestDeferredLane() {
@@ -18839,10 +18837,10 @@ __DEV__ &&
     (function () {
       var internals = {
         bundleType: 1,
-        version: "19.2.0-www-modern-0cac32d6-20250513",
+        version: "19.2.0-www-modern-676f0879-20250513",
         rendererPackageName: "react-art",
         currentDispatcherRef: ReactSharedInternals,
-        reconcilerVersion: "19.2.0-www-modern-0cac32d6-20250513"
+        reconcilerVersion: "19.2.0-www-modern-676f0879-20250513"
       };
       internals.overrideHookState = overrideHookState;
       internals.overrideHookStateDeletePath = overrideHookStateDeletePath;
@@ -18876,7 +18874,7 @@ __DEV__ &&
     exports.Shape = Shape;
     exports.Surface = Surface;
     exports.Text = Text;
-    exports.version = "19.2.0-www-modern-0cac32d6-20250513";
+    exports.version = "19.2.0-www-modern-676f0879-20250513";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&