fix(gatsby): fix DSG special char 404 issue (#35336)

Author: marvinjude

e2e-tests/production-runtime/cypress/integration/1-production.js

@@ -131,6 +131,21 @@ describe(`Production build tests`, () => {
   })
 
   describe(`Supports unicode characters in urls`, () => {
+    describe(`DSG pages`, () => {
+      it(`Can navigate directly`, () => {
+        cy.visit(encodeURI(`/한글-URL`)).waitForRouteChange()
+        cy.getTestElement(`dom-marker`).contains("page-2")
+      })
+
+      it(`Can navigate on client`, () => {
+        cy.visit(`/`).waitForRouteChange()
+        cy.getTestElement(`dsg-page-with-unicode-path`)
+          .click()
+          .waitForRouteChange()
+        cy.getTestElement(`dom-marker`).contains("page-2")
+      })
+    })
+
     it(`Can navigate directly`, () => {
       cy.visit(encodeURI(`/안녕/`), {
         // Cypress seems to think it's 404

e2e-tests/production-runtime/gatsby-node.js

@@ -105,6 +105,12 @@ exports.createPages = ({ actions: { createPage, createRedirect } }) => {
     component: path.resolve(`src/pages/page-2.js`),
   })
 
+  createPage({
+    path: `/한글-URL`,
+    component: path.resolve(`src/pages/page-2.js`),
+    defer: true,
+  })
+
   createPage({
     path: `/foo/@something/bar`,
     component: path.resolve(`src/pages/page-2.js`),

e2e-tests/production-runtime/src/pages/index.js

@@ -61,6 +61,11 @@ const IndexPage = ({ pageContext }) => (
           Go to page with unicode path
         </Link>
       </li>
+      <li>
+        <Link to="/한글-URL" data-testid="dsg-page-with-unicode-path">
+          Go to DSG page with unicode path
+        </Link>
+      </li>
       <li>
         <Link to="/foo/@something/bar" data-testid="page-with-encodable-path">
           Go to page with unicode path

packages/gatsby/src/utils/find-page-by-path.ts

@@ -47,6 +47,8 @@ export function findPageByPath(
 ): IGatsbyPage | undefined {
   const { pages } = state
 
+  path = decodeURIComponent(path)
+
   // first check by exact path
   let page = pages.get(path)
   if (page) {