Allow external image urls with _next/image pathname to be rendered vi…

…a Image component (#69586)

### What?
Fixes #69456 which describes an issue with `next/image` component, where
an external image containing `_next/image` in the URL fails with the
error `"url" parameter cannot be recursive`.

### Why?
The `next/image` component should be able to render images from
configured hostnames without doing the recursive check.

### How?
Before checking for the existence of `_next/image` substring in the
image's path, we can simply check if the image is an external URL that
comes from a preconfigured host in the `next.config.js` file.

Example:
<img width="1207" alt="image"
src="https://github.com/user-attachments/assets/8d5c99cf-f050-40a9-b5a4-ba961b83f037">

---------

Co-authored-by: Steven <steven@ceriously.com>

packages/next/src/server/image-optimizer.ts

@@ -198,21 +198,20 @@ export class ImageOptimizerCache {
       }
     }
 
-    const parsedUrl = parseUrl(url)
-    if (parsedUrl) {
-      const decodedPathname = decodeURIComponent(parsedUrl.pathname)
-      if (/\/_next\/image($|\/)/.test(decodedPathname)) {
-        return {
-          errorMessage: '"url" parameter cannot be recursive',
-        }
-      }
-    }
-
     let isAbsolute: boolean
 
     if (url.startsWith('/')) {
       href = url
       isAbsolute = false
+      if (
+        /\/_next\/image($|\/)/.test(
+          decodeURIComponent(parseUrl(url)?.pathname ?? '')
+        )
+      ) {
+        return {
+          errorMessage: '"url" parameter cannot be recursive',
+        }
+      }
     } else {
       let hrefParsed: URL
 

test/integration/image-optimizer/test/util.ts

@@ -8,7 +8,6 @@ import {
   fetchViaHTTP,
   File,
   findPort,
-  getFetchUrl,
   killApp,
   launchApp,
   nextBuild,
@@ -899,22 +898,28 @@ export function runTests(ctx) {
       expect(await res.text()).toBe(`"url" parameter is invalid`)
     })
 
-    it('should fail with absolute next image url', async () => {
-      const fullUrl = getFetchUrl(
-        ctx.appPort,
-        '/_next/image?url=test.pngw=1&q=1'
-      )
-      const query = { url: fullUrl, w: ctx.w, q: 1 }
-      const res = await fetchViaHTTP(ctx.appPort, '/_next/image', query, {})
-      expect(res.status).toBe(400)
-      expect(await res.text()).toBe(`"url" parameter cannot be recursive`)
-    })
+    if (domains.length > 0) {
+      it('should pass with absolute next image url', async () => {
+        const fullUrl =
+          'https://image-optimization-test.vercel.app/_next/image?url=%2Ffrog.jpg&w=1024&q=75'
+        const query = { url: fullUrl, w: ctx.w, q: 1 }
+        const res = await fetchViaHTTP(ctx.appPort, '/_next/image', query, {})
+        expect(res.status).toBe(200)
+        await expectWidth(res, ctx.w)
+      })
+    } else {
+      it('should fail with absolute next image url', async () => {
+        const fullUrl =
+          'https://image-optimization-test.vercel.app/_next/image?url=%2Ffrog.jpg&w=1024&q=75'
+        const query = { url: fullUrl, w: ctx.w, q: 1 }
+        const res = await fetchViaHTTP(ctx.appPort, '/_next/image', query, {})
+        expect(res.status).toBe(400)
+        expect(await res.text()).toBe(`"url" parameter is not allowed`)
+      })
+    }
 
     it('should fail with relative image url with assetPrefix', async () => {
-      const fullUrl = getFetchUrl(
-        ctx.appPort,
-        `/assets/_next/image?url=test.pngw=1&q=1`
-      )
+      const fullUrl = '/assets/_next/image?url=%2Ftest.png&w=128&q=75'
       const query = { url: fullUrl, w: ctx.w, q: 1 }
       const res = await fetchViaHTTP(ctx.appPort, '/_next/image', query, {})
       expect(res.status).toBe(400)