SlotFill: Allow contextual SlotFillProviders

packages/block-editor/src/components/provider/index.js

@@ -45,7 +45,7 @@ export const ExperimentalBlockEditorProvider = withRegistryProvider(
 		useBlockSync( props );
 
 		return (
-			<SlotFillProvider>
+			<SlotFillProvider passthrough>
 				<KeyboardShortcuts.Register />
 				<BlockRefsProvider>{ children }</BlockRefsProvider>
 			</SlotFillProvider>

packages/components/CHANGELOG.md

@@ -17,6 +17,7 @@
 -   `ToggleGroupControl`: react correctly to external controlled updates ([#56678](https://github.com/WordPress/gutenberg/pull/56678)).
 -   `ToolsPanel`: fix a performance issue ([#56770](https://github.com/WordPress/gutenberg/pull/56770)).
 -   `BorderControl`: adjust `BorderControlDropdown` Button size to fix misaligned border ([#56730](https://github.com/WordPress/gutenberg/pull/56730)).
+-   `SlotFillProvider`: Restore contextual Slot/Fills within SlotFillProvider ([#56779](https://github.com/WordPress/gutenberg/pull/56779)).
 
 ### Internal
 

packages/components/src/slot-fill/index.tsx

@@ -55,9 +55,12 @@ export function UnforwardedSlot(
 }
 export const Slot = forwardRef( UnforwardedSlot );
 
-export function Provider( { children }: SlotFillProviderProps ) {
+export function Provider( {
+	children,
+	passthrough = false,
+}: SlotFillProviderProps ) {
 	const parent = useContext( SlotFillContext );
-	if ( ! parent.isDefault ) {
+	if ( ! parent.isDefault && passthrough ) {
 		return <>{ children }</>;
 	}
 	return (

packages/components/src/slot-fill/types.ts

@@ -96,6 +96,11 @@ export type SlotFillProviderProps = {
 	 * The children elements.
 	 */
 	children: ReactNode;
+
+	/**
+	 * Whether to pass slots to the parent provider if existent.
+	 */
+	passthrough?: boolean;
 };
 
 export type SlotFillBubblesVirtuallySlotRef = RefObject< HTMLElement >;