Fix Windows path normalization regressions in state discovery and terminal folder links

src/platform/path-adapter.ts

@@ -23,10 +23,14 @@ function removeTrailingSeparators(
   value: string,
   parser: typeof path.posix | typeof path.win32,
 ): string {
-  const root = parser.parse(value).root;
+  const root = Math.max(
+    parser.parse(value).root.length,
+    path.posix.parse(value).root.length,
+    path.win32.parse(value).root.length,
+  );
   let end = value.length;
   while (
-    end > root.length &&
+    end > root &&
     (value[end - 1] === "/" || value[end - 1] === "\\")
   ) {
     end -= 1;
@@ -65,7 +69,7 @@ export function createPathAdapter(options: PathAdapterOptions): PathAdapter {
       options.platform,
       options.homeDirectory,
     );
-    const normalized = parser.isAbsolute(expanded)
+    const normalized = path.posix.isAbsolute(expanded) || path.win32.isAbsolute(expanded)
       ? parser.normalize(expanded)
       : parser.resolve(normalizedCwd, expanded);
     return removeTrailingSeparators(normalized, parser);

src/state/discovery.ts

@@ -20,6 +20,10 @@ function nativePlatform(): PathPlatform {
   return process.platform === "win32" ? "win32" : "posix";
 }
 
+function isAbsolutePath(value: string): boolean {
+  return path.posix.isAbsolute(value) || path.win32.isAbsolute(value);
+}
+
 export function resolveStateLocation(
   options: StateLocationOptions = {},
 ): StateLocation {
@@ -38,7 +42,9 @@ export function resolveStateLocation(
     throw new Error("Codex home must not be empty");
   }
 
-  const codexHome = parser.resolve(cwd, configuredHome);
+  const codexHome = isAbsolutePath(configuredHome)
+    ? configuredHome
+    : parser.resolve(cwd, configuredHome);
   return {
     codexHome,
     configDirectory: parser.join(userHome, ".config", "codex-project"),

src/terminal/style.ts

@@ -106,7 +106,15 @@ export function folderLink(
     { tone: "folder", underline: options.hyperlinks === true },
     options,
   );
-  return hyperlink(text, pathToFileURL(folder).href, options);
+  const normalized = folder.replaceAll("\\", "/");
+  const uri = /^[A-Za-z]:\//.test(normalized)
+    ? `file:///${encodeURI(normalized)}`
+    : normalized.startsWith("//")
+      ? `file:${encodeURI(normalized)}`
+      : normalized.startsWith("/")
+        ? `file://${encodeURI(normalized)}`
+      : pathToFileURL(folder).href;
+  return hyperlink(text, uri, options);
 }
 
 export interface DetectTerminalStyleOptions {

test/unit/path-adapter.test.ts

@@ -25,6 +25,10 @@ describe("POSIX path adapter", () => {
     expect(paths.normalize("/")).toBe("/");
   });
 
+  it("preserves absolute Windows paths in POSIX mode", () => {
+    expect(paths.normalize("C:\\Work\\Alpha\\")).toBe("C:\\Work\\Alpha");
+  });
+
   it("keeps POSIX comparisons case-sensitive", () => {
     expect(paths.equals("/Work/Alpha", "/Work/Alpha/")).toBe(true);
     expect(paths.equals("/Work/Alpha", "/work/alpha")).toBe(false);

test/unit/state-discovery.test.ts

@@ -54,4 +54,21 @@ describe("state discovery", () => {
         "C:\\work\\tests\\fixture-home\\.codex-global-state.json",
     });
   });
+
+  it("keeps absolute Windows Codex home unchanged in posix-mode resolution", () => {
+    expect(
+      resolveStateLocation({
+        codexHome: "C:\\Users\\Example\\AppData\\Local\\Temp\\codex-home",
+        cwd: "D:\\work\\repo",
+        env: {},
+        platform: "posix",
+        userHome: "/Users/example",
+      }),
+    ).toEqual({
+      codexHome: "C:\\Users\\Example\\AppData\\Local\\Temp\\codex-home",
+      configDirectory: "/Users/example/.config/codex-project",
+      stateFile:
+        "C:\\Users\\Example\\AppData\\Local\\Temp\\codex-home/.codex-global-state.json",
+    });
+  });
 });

test/unit/terminal-style.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { detectTerminalStyle } from "../../src/terminal/style.js";
+import { detectTerminalStyle, folderLink } from "../../src/terminal/style.js";
 
 describe("terminal style detection", () => {
   it("enables colors and hyperlinks for an interactive terminal", () => {
@@ -46,4 +46,12 @@ describe("terminal style detection", () => {
       }),
     ).toEqual({ colors: true, hyperlinks: true });
   });
+
+  it("formats absolute paths into stable file hyperlinks", () => {
+    const linked = folderLink("/work/rose garden", {
+      colors: false,
+      hyperlinks: true,
+    });
+    expect(linked).toContain("\u001B]8;;file:///work/rose%20garden\u001B\\");
+  });
 });