fix: Handle sanitizeUrl can receive non-string value

closes #3746

app/editor/components/LinkEditor.tsx

@@ -113,7 +113,7 @@ class LinkEditor extends React.Component<Props, State> {
 
     this.discardInputValue = true;
     const { from, to } = this.props;
-    href = sanitizeHref(href);
+    href = sanitizeHref(href) ?? "";
 
     this.props.onSelectLink({ href, title, from, to });
   };

shared/utils/urls.ts

@@ -77,7 +77,11 @@ export function isExternalUrl(url: string) {
  * @param href The href to sanitize
  * @returns The sanitized href
  */
-export function sanitizeHref(href: string) {
+export function sanitizeHref(href: string | null | undefined) {
+  if (!href) {
+    return undefined;
+  }
+
   if (
     !isUrl(href) &&
     !href.startsWith("/") &&