From 65daaa7022c8ad27b8fc203b5396f840da88f713 Mon Sep 17 00:00:00 2001
From: Miguel Sandoval <malejandro27@outlook.com>
Date: Wed, 13 Dec 2023 16:53:00 -0800
Subject: [PATCH] Avoid duplicate base prefix applied on ssr when assets plugin
 applied before html transforms

---
 .../src/node/server/middlewares/indexHtml.ts  | 28 ++++++++++---------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/packages/vite/src/node/server/middlewares/indexHtml.ts b/packages/vite/src/node/server/middlewares/indexHtml.ts
index 4ebc2a41e86bfe..85375323e4c2d7 100644
--- a/packages/vite/src/node/server/middlewares/indexHtml.ts
+++ b/packages/vite/src/node/server/middlewares/indexHtml.ts
@@ -138,19 +138,21 @@ const processNodeUrl = (
     }
 
     if (
-      (url[0] === '/' && url[1] !== '/') ||
-      // #3230 if some request url (localhost:3000/a/b) return to fallback html, the relative assets
-      // path will add `/a/` prefix, it will caused 404.
-      //
-      // skip if url contains `:` as it implies a url protocol or Windows path that we don't want to replace.
-      //
-      // rewrite `./index.js` -> `localhost:5173/a/index.js`.
-      // rewrite `../index.js` -> `localhost:5173/index.js`.
-      // rewrite `relative/index.js` -> `localhost:5173/a/relative/index.js`.
-      ((url[0] === '.' || isBareRelative(url)) &&
-        originalUrl &&
-        originalUrl !== '/' &&
-        htmlPath === '/index.html')
+      // avoid duplicate base prefix when applying html transforms after assets plugin
+      !url.startsWith(config.base) &&
+      ((url[0] === '/' && url[1] !== '/') ||
+        // #3230 if some request url (localhost:3000/a/b) return to fallback html, the relative assets
+        // path will add `/a/` prefix, it will caused 404.
+        //
+        // skip if url contains `:` as it implies a url protocol or Windows path that we don't want to replace.
+        //
+        // rewrite `./index.js` -> `localhost:5173/a/index.js`.
+        // rewrite `../index.js` -> `localhost:5173/index.js`.
+        // rewrite `relative/index.js` -> `localhost:5173/a/relative/index.js`.
+        ((url[0] === '.' || isBareRelative(url)) &&
+          originalUrl &&
+          originalUrl !== '/' &&
+          htmlPath === '/index.html'))
     ) {
       url = path.posix.join(config.base, url)
     }