fix(Link): Do not ignore onMouseEnter prop with absolute href (vercel#32012)

Fixes vercel#22733

Regardless of whether it's recommended that Link be used with external href values or not, they can be used and `onMouseEnter` being swallowed with an external href value is unexpected behavior.

## Bug

- [x] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`

## Documentation / Examples

- [x] Make sure the linting passes by running `yarn lint`

Author: ericmatthys

packages/next/client/link.tsx

@@ -291,11 +291,12 @@ function Link(props: React.PropsWithChildren<LinkProps>) {
   }
 
   childProps.onMouseEnter = (e: React.MouseEvent) => {
-    if (!isLocalURL(href)) return
     if (child.props && typeof child.props.onMouseEnter === 'function') {
       child.props.onMouseEnter(e)
     }
-    prefetch(router, href, as, { priority: true })
+    if (isLocalURL(href)) {
+      prefetch(router, href, as, { priority: true })
+    }
   }
 
   // If child is an <a> tag and doesn't have a href attribute, or if the 'passHref' property is

test/integration/client-navigation/pages/absolute-url.js

@@ -11,6 +11,8 @@ export async function getServerSideProps({ query: { port } }) {
 
 export default function Page({ port }) {
   const router = useRouter()
+  const [hover, setHover] = React.useState(false)
+
   return (
     <>
       <Link href="https://vercel.com/">
@@ -61,6 +63,17 @@ export default function Page({ port }) {
       <Link href="mailto:[email protected]">
         <a id="mailto-link">mailto:[email protected]</a>
       </Link>
+      <br />
+      <Link href="https://vercel.com/">
+        <a
+          id="absolute-link-mouse-events"
+          data-hover={hover}
+          onMouseEnter={() => setHover(true)}
+          onMouseLeave={() => setHover(false)}
+        >
+          https://vercel.com/
+        </a>
+      </Link>
     </>
   )
 }

test/integration/client-navigation/test/index.test.js

@@ -118,6 +118,21 @@ describe('Client Navigation', () => {
       )
     })
 
+    it('should call mouse handlers with an absolute url', async () => {
+      const browser = await webdriver(
+        context.appPort,
+        `/absolute-url?port=${context.appPort}`
+      )
+
+      await browser.elementByCss('#absolute-link-mouse-events').moveTo()
+
+      expect(
+        await browser
+          .waitForElementByCss('#absolute-link-mouse-events')
+          .getAttribute('data-hover')
+      ).toBe('true')
+    })
+
     it('should navigate an absolute local url', async () => {
       const browser = await webdriver(
         context.appPort,