From e1e426e45de51660a48e832775007e7731db07f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=BF=A0=20/=20green?= <green@sapphi.red>
Date: Tue, 28 Jun 2022 15:38:31 +0900
Subject: [PATCH] fix: incorrectly resolving `knownJsSrcRE` files from root
 (fixes #4161) (#8808)

---
 packages/vite/src/node/plugins/resolve.ts |  9 ++++++---
 packages/vite/src/node/utils.ts           | 11 +++++++++++
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/packages/vite/src/node/plugins/resolve.ts b/packages/vite/src/node/plugins/resolve.ts
index 4acbfbaf816678..76fcfcbdb298f4 100644
--- a/packages/vite/src/node/plugins/resolve.ts
+++ b/packages/vite/src/node/plugins/resolve.ts
@@ -24,6 +24,7 @@ import {
   isDataUrl,
   isExternalUrl,
   isFileReadable,
+  isNonDriveRelativeAbsolutePath,
   isObject,
   isPossibleTsOutput,
   isTsRequest,
@@ -172,8 +173,7 @@ export function resolvePlugin(resolveOptions: InternalResolveOptions): Plugin {
       // relative
       if (
         id.startsWith('.') ||
-        (preferRelative && /^\w/.test(id)) ||
-        importer?.endsWith('.html')
+        ((preferRelative || importer?.endsWith('.html')) && /^\w/.test(id))
       ) {
         const basedir = importer ? path.dirname(importer) : process.cwd()
         const fsPath = path.resolve(basedir, id)
@@ -239,7 +239,10 @@ export function resolvePlugin(resolveOptions: InternalResolveOptions): Plugin {
       }
 
       // absolute fs paths
-      if (path.isAbsolute(id) && (res = tryFsResolve(id, options))) {
+      if (
+        isNonDriveRelativeAbsolutePath(id) &&
+        (res = tryFsResolve(id, options))
+      ) {
         isDebug && debug(`[fs] ${colors.cyan(id)} -> ${colors.dim(res)}`)
         return res
       }
diff --git a/packages/vite/src/node/utils.ts b/packages/vite/src/node/utils.ts
index e2c7c8862b930a..796f95a35f6667 100644
--- a/packages/vite/src/node/utils.ts
+++ b/packages/vite/src/node/utils.ts
@@ -1063,3 +1063,14 @@ export function stripBomTag(content: string): string {
 }
 
 export const isTS = (filename: string): boolean => /\.[cm]?ts$/.test(filename)
+
+const windowsDrivePathPrefixRE = /^[A-Za-z]:[/\\]/
+
+/**
+ * path.isAbsolute also returns true for drive relative paths on windows (e.g. /something)
+ * this function returns false for them but true for absolute paths (e.g. C:/something)
+ */
+export const isNonDriveRelativeAbsolutePath = (p: string): boolean => {
+  if (!isWindows) return p.startsWith('/')
+  return windowsDrivePathPrefixRE.test(p)
+}