[Fiber] Avoid duplicate debug info for array children

Author: eps1lon

packages/react-devtools-shared/src/__tests__/store-test.js

@@ -2857,8 +2857,7 @@ describe('Store', () => {
     expect(store).toMatchInlineSnapshot(`
       [root]
         ▾ <App> [Server]
-          ▾ <App> [Server]
-              <ClientComponent key="app">
+            <ClientComponent key="app">
     `);
   });
 

packages/react-reconciler/src/ReactChildFiber.js

@@ -789,6 +789,7 @@ function createChildReconciler(
           // We treat the parent as the owner for stack purposes.
           created._debugOwner = returnFiber;
           created._debugTask = returnFiber._debugTask;
+          // Make sure to not push again when handling the Fragment child.
           const prevDebugInfo = pushDebugInfo(newChild._debugInfo);
           created._debugInfo = currentDebugInfo;
           currentDebugInfo = prevDebugInfo;
@@ -1915,41 +1916,41 @@ function createChildReconciler(
       }
 
       if (isArray(newChild)) {
-        const prevDebugInfo = pushDebugInfo(newChild._debugInfo);
+        // We created a Fragment for this child with the debug info.
+        // No need to push again.
         const firstChild = reconcileChildrenArray(
           returnFiber,
           currentFirstChild,
           newChild,
           lanes,
         );
-        currentDebugInfo = prevDebugInfo;
         return firstChild;
       }
 
       if (getIteratorFn(newChild)) {
-        const prevDebugInfo = pushDebugInfo(newChild._debugInfo);
+        // We created a Fragment for this child with the debug info.
+        // No need to push again.
         const firstChild = reconcileChildrenIteratable(
           returnFiber,
           currentFirstChild,
           newChild,
           lanes,
         );
-        currentDebugInfo = prevDebugInfo;
         return firstChild;
       }
 
       if (
         enableAsyncIterableChildren &&
         typeof newChild[ASYNC_ITERATOR] === 'function'
       ) {
-        const prevDebugInfo = pushDebugInfo(newChild._debugInfo);
+        // We created a Fragment for this child with the debug info.
+        // No need to push again.
         const firstChild = reconcileChildrenAsyncIteratable(
           returnFiber,
           currentFirstChild,
           newChild,
           lanes,
         );
-        currentDebugInfo = prevDebugInfo;
         return firstChild;
       }