fix: Add Next-Url to http vary in consideration of intercept routes.

packages/next/src/client/components/app-router-headers.ts

@@ -7,7 +7,7 @@ export const NEXT_URL = 'Next-Url' as const
 export const FETCH_CACHE_HEADER = 'x-vercel-sc-headers' as const
 export const RSC_CONTENT_TYPE_HEADER = 'text/x-component' as const
 export const RSC_VARY_HEADER =
-  `${RSC}, ${NEXT_ROUTER_STATE_TREE}, ${NEXT_ROUTER_PREFETCH}` as const
+  `${RSC}, ${NEXT_ROUTER_STATE_TREE}, ${NEXT_ROUTER_PREFETCH}, ${NEXT_URL}` as const
 
 export const FLIGHT_PARAMETERS = [
   [RSC],

packages/next/src/client/components/router-reducer/fetch-server-response.ts

@@ -72,6 +72,7 @@ export async function fetchServerResponse(
     [
       headers[NEXT_ROUTER_PREFETCH] || '0',
       headers[NEXT_ROUTER_STATE_TREE],
+      headers[NEXT_URL],
     ].join(',')
   )
 

test/e2e/app-dir/app-prefetch/app/dashboard/page.js

@@ -1,3 +1,5 @@
+import Link from 'next/link'
+
 export const revalidate = 0
 
 async function getData() {
@@ -12,6 +14,9 @@ export default async function DashboardPage(props) {
   return (
     <>
       <p id="dashboard-page">{message}</p>
+      <Link href="/static-page" id="to-static-page">
+        To Static Page
+      </Link>
     </>
   )
 }

test/e2e/app-dir/app-prefetch/prefetching.test.ts

@@ -157,6 +157,43 @@ createNextDescribe(
       ).toBe(1)
     })
 
+    it('should calculate `_rsc` query based on `Next-Url`', async () => {
+      const browser = await next.browser('/404', browserConfigWithFixedTime)
+      let staticPageRequests: string[] = []
+
+      browser.on('request', (req) => {
+        const url = new URL(req.url())
+        if (url.toString().includes(`/static-page?${NEXT_RSC_UNION_QUERY}=`)) {
+          staticPageRequests.push(`${url.pathname}${url.search}`)
+        }
+      })
+      await browser.eval('location.href = "/"')
+      await browser.eval(
+        `window.nd.router.prefetch("/static-page", {kind: "auto"})`
+      )
+      await check(() => {
+        return staticPageRequests.length === 1
+          ? 'success'
+          : JSON.stringify(staticPageRequests)
+      }, 'success')
+
+      // Unable to clear router cache so mpa navigation
+      await browser.eval('location.href = "/dashboard"')
+      await browser.eval(
+        `window.nd.router.prefetch("/static-page", {kind: "auto"})`
+      )
+      await check(() => {
+        return staticPageRequests.length === 2
+          ? 'success'
+          : JSON.stringify(staticPageRequests)
+      }, 'success')
+
+      expect(staticPageRequests[0]).toMatch('/static-page?_rsc=')
+      expect(staticPageRequests[1]).toMatch('/static-page?_rsc=')
+      // `_rsc` does not match because it depends on the `Next-Url`
+      expect(staticPageRequests[0]).not.toBe(staticPageRequests[1])
+    })
+
     it('should not prefetch for a bot user agent', async () => {
       const browser = await next.browser('/404')
       let requests: string[] = []

test/e2e/app-dir/app/index.test.ts

@@ -256,8 +256,8 @@ createNextDescribe(
       expect(res.headers.get('x-edge-runtime')).toBe('1')
       expect(res.headers.get('vary')).toBe(
         isNextDeploy
-          ? 'RSC, Next-Router-State-Tree, Next-Router-Prefetch'
-          : 'RSC, Next-Router-State-Tree, Next-Router-Prefetch, Accept-Encoding'
+          ? 'RSC, Next-Router-State-Tree, Next-Router-Prefetch, Next-Url'
+          : 'RSC, Next-Router-State-Tree, Next-Router-Prefetch, Next-Url, Accept-Encoding'
       )
     })
 
@@ -269,8 +269,8 @@ createNextDescribe(
       })
       expect(res.headers.get('vary')).toBe(
         isNextDeploy
-          ? 'RSC, Next-Router-State-Tree, Next-Router-Prefetch'
-          : 'RSC, Next-Router-State-Tree, Next-Router-Prefetch, Accept-Encoding'
+          ? 'RSC, Next-Router-State-Tree, Next-Router-Prefetch, Next-Url'
+          : 'RSC, Next-Router-State-Tree, Next-Router-Prefetch, Next-Url, Accept-Encoding'
       )
     })
 

test/integration/dynamic-routing/test/index.test.js

@@ -1462,7 +1462,8 @@ function runTests({ dev }) {
         rsc: {
           header: 'RSC',
           contentTypeHeader: 'text/x-component',
-          varyHeader: 'RSC, Next-Router-State-Tree, Next-Router-Prefetch',
+          varyHeader:
+            'RSC, Next-Router-State-Tree, Next-Router-Prefetch, Next-Url',
         },
       })
     })