Force remount LinkControl when moving between links within same richt…

…ext block (#34742)

* Force remount LinkControl within Popovers

* Use anchor ref as semi-unique value to force remount

* Use the HTML string of the anchor onto which the linkcontrol is attached as the remount key

* Use custom key based unique ID generator

packages/format-library/src/link/inline.js

@@ -26,6 +26,7 @@ import { useSelect } from '@wordpress/data';
  */
 import { createLinkFormat, isValidHref, getFormatBoundary } from './utils';
 import { link as settings } from './index';
+import useLinkInstanceKey from './use-link-instance-key';
 
 function InlineLinkUI( {
 	isActive,
@@ -184,6 +185,12 @@ function InlineLinkUI( {
 
 	const anchorRef = useAnchorRef( { ref: contentRef, value, settings } );
 
+	// Generate a string based key that is unique to this anchor reference.
+	// This is used to force re-mount the LinkControl component to avoid
+	// potential stale state bugs caused by the component not being remounted
+	// See https://github.com/WordPress/gutenberg/pull/34742.
+	const forceRemountKey = useLinkInstanceKey( anchorRef );
+
 	// The focusOnMount prop shouldn't evolve during render of a Popover
 	// otherwise it causes a render of the content.
 	const focusOnMount = useRef( addingLink ? 'firstElement' : false );
@@ -222,6 +229,7 @@ function InlineLinkUI( {
 			position="bottom center"
 		>
 			<LinkControl
+				key={ forceRemountKey }
 				value={ linkValue }
 				onChange={ onChangeLink }
 				onRemove={ removeLink }

packages/format-library/src/link/use-link-instance-key.js

@@ -0,0 +1,31 @@
+// Weakly referenced map allows unused ids to be garbage collected.
+const weakMap = new WeakMap();
+
+// Incrementing zero-based ID value
+let id = -1;
+
+const prefix = 'link-control-instance';
+
+function getKey( _id ) {
+	return `${ prefix }-${ _id }`;
+}
+
+/**
+ * Builds a unique link control key for the given object reference.
+ *
+ * @param {Object} instance an unique object reference specific to this link control instance.
+ * @return {string} the unique key to use for this link control.
+ */
+function useLinkInstanceKey( instance ) {
+	if ( weakMap.has( instance ) ) {
+		return getKey( weakMap.get( instance ) );
+	}
+
+	id += 1;
+
+	weakMap.set( instance, id );
+
+	return getKey( id );
+}
+
+export default useLinkInstanceKey;