fix: skip WSL System32 bash.exe in Windows Git Bash detection

Author: qorzj

src/common/shell-utils.ts

@@ -175,13 +175,17 @@ function findAllWindowsExecutableCandidates(executable: string): string[] {
       stdio: ["ignore", "pipe", "ignore"],
       windowsHide: true,
     });
-    return filterWindowsExecutableCandidates([
-      ...output
-        .split(/\r?\n/)
-        .map((line) => line.trim())
-        .filter(Boolean),
-      ...extraCandidates,
-    ]);
+    let whereResults = output
+      .split(/\r?\n/)
+      .map((line) => line.trim())
+      .filter(Boolean);
+    if (executable === "bash") {
+      // Skip WSL's deprecated bash.exe launcher (C:\Windows\System32\bash.exe).
+      // It would start commands inside the Linux distro instead of the Windows host,
+      // breaking all path translations and tool invocations.
+      whereResults = whereResults.filter((candidate) => !/system32[\\/]bash\.exe$/i.test(candidate));
+    }
+    return filterWindowsExecutableCandidates([...whereResults, ...extraCandidates]);
   } catch {
     return filterWindowsExecutableCandidates(extraCandidates);
   }

src/tests/shell-utils.test.ts

@@ -72,6 +72,23 @@ test("Windows Git Bash detection derives bash.exe from git.exe candidates", () =
   assert.equal(resolved, bashPath);
 });
 
+test("Windows Git Bash detection skips WSL System32 bash.exe in PATH results", () => {
+  // When WSL1 is enabled on older Windows 10, C:\Windows\System32\bash.exe
+  // appears in PATH. That launcher would execute commands inside the Linux
+  // distro instead of the Windows host, breaking all tool invocations.
+  // The PATH bash strategy should ignore it and fall through.
+  const system32Bash = "C:\\Windows\\System32\\bash.exe";
+  const gitBash = "D:\\Tools\\Git\\bin\\bash.exe";
+  const resolved = resolveWindowsGitBashPath({
+    findExecutableCandidates: (executable) =>
+      executable === "bash" ? [system32Bash] : executable === "git" ? ["D:\\Tools\\Git\\cmd\\git.exe"] : [],
+    findGitExecPath: () => null,
+    existsSync: (candidate) => candidate === gitBash,
+  });
+
+  assert.equal(resolved, gitBash);
+});
+
 test("File tool path normalization converts Git Bash drive paths on Windows", () => {
   assert.equal(
     normalizeFilePath("/d/IdeaProjects/guesswho-api/API_DOCUMENTATION.md", "win32"),