Handle broken links in header and footer (#3663)

Co-authored-by: Nicolas Dorseuil <nicolas@gitbook.io>

Author: conico974

packages/gitbook/src/components/Footer/FooterLinksGroup.tsx

@@ -36,13 +36,9 @@ async function FooterLink(props: { link: CustomizationContentLink; context: GitB
     const { link, context } = props;
     const resolved = await resolveContentRef(link.to, context);
 
-    if (!resolved) {
-        return null;
-    }
-
     return (
         <Link
-            href={resolved.href}
+            href={resolved?.href ?? '#'}
             className={tcls(
                 'font-normal',
                 'text-tint',

packages/gitbook/src/components/Header/HeaderLink.tsx

@@ -57,7 +57,7 @@ export async function HeaderLink(props: {
         );
     }
 
-    if (!target || !link.to) {
+    if (!link.to) {
         return null;
     }
 
@@ -68,7 +68,7 @@ export async function HeaderLink(props: {
             headerPreset={headerPreset}
             title={link.title}
             isDropdown={false}
-            href={target.href}
+            href={target?.href}
         />
     );
 }
@@ -78,7 +78,7 @@ export type HeaderLinkNavItemProps = {
     linkStyle: NonNullable<CustomizationHeaderItem['style']>;
     headerPreset: CustomizationHeaderPreset;
     title: string;
-    href: string;
+    href?: string;
     isDropdown: boolean;
 } & DropdownButtonProps<HTMLElement>;
 
@@ -165,7 +165,7 @@ function HeaderItemLink(props: Omit<HeaderLinkNavItemProps, 'linkStyle'>) {
     const { linkTarget, headerPreset, title, isDropdown, href, ...rest } = props;
     return (
         <Link
-            href={href}
+            href={href ?? '#'}
             className={getHeaderLinkClassName({ headerPreset })}
             insights={{
                 type: 'link_click',