Add Placement bit without removing others (#20398)
When scheduling a Placement effect, we should add the Placement bit without resetting the others. In the old fork, there are no flags to reset, anyway, since by the time we reach the child reconciler, the flags will have already been reset. However, in the effects refactor, "static" flags are not reset, so this can actually manifest as a bug. See #20285 for a regression test.
Andrew Clark committed
Dec 7, 2020 at 15:07 UTC
1377e465ddc492a1b4b33d75e652bce9b273cc85
2 files changed
+6
-6
packages/react-reconciler/src/ReactChildFiber.new.js
+3
-3
@@ -342,7 +342,7 @@ function ChildReconciler(shouldTrackSideEffects) {
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const oldIndex = current.index;
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if (oldIndex < lastPlacedIndex) {
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// This is a move.
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- newFiber.flags = Placement;
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+ newFiber.flags |= Placement;
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return lastPlacedIndex;
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} else {
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// This item can stay in place.
@@ -350,7 +350,7 @@ function ChildReconciler(shouldTrackSideEffects) {
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}
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} else {
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// This is an insertion.
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- newFiber.flags = Placement;
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+ newFiber.flags |= Placement;
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return lastPlacedIndex;
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}
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}
@@ -359,7 +359,7 @@ function ChildReconciler(shouldTrackSideEffects) {
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// This is simpler for the single child case. We only need to do a
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// placement for inserting new children.
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if (shouldTrackSideEffects && newFiber.alternate === null) {
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- newFiber.flags = Placement;
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+ newFiber.flags |= Placement;
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}
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return newFiber;
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}
packages/react-reconciler/src/ReactChildFiber.old.js
+3
-3
@@ -342,7 +342,7 @@ function ChildReconciler(shouldTrackSideEffects) {
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const oldIndex = current.index;
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if (oldIndex < lastPlacedIndex) {
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// This is a move.
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- newFiber.flags = Placement;
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+ newFiber.flags |= Placement;
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return lastPlacedIndex;
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} else {
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// This item can stay in place.
@@ -350,7 +350,7 @@ function ChildReconciler(shouldTrackSideEffects) {
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}
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} else {
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// This is an insertion.
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- newFiber.flags = Placement;
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+ newFiber.flags |= Placement;
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return lastPlacedIndex;
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}
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}
@@ -359,7 +359,7 @@ function ChildReconciler(shouldTrackSideEffects) {
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// This is simpler for the single child case. We only need to do a
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// placement for inserting new children.
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if (shouldTrackSideEffects && newFiber.alternate === null) {
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- newFiber.flags = Placement;
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+ newFiber.flags |= Placement;
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}
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return newFiber;
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}