Fix WSL sessions not starting in home directory on newer Windows builds (#11663)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Eugene <inbox@null.page>

tabby-core/src/utils.ts

@@ -5,6 +5,7 @@ import { marker as _ } from '@biesbjerg/ngx-translate-extract-marker'
 export const WIN_BUILD_CONPTY_SUPPORTED = 17692
 export const WIN_BUILD_CONPTY_STABLE = 18309
 export const WIN_BUILD_WSL_EXE_DISTRO_FLAG = 17763
+export const WIN_BUILD_WSL_EXE_CD_FLAG = 19041
 export const WIN_BUILD_FLUENT_BG_SUPPORTED = 17063
 
 export function getWindows10Build (): number|undefined {

tabby-electron/src/shells/wsl.ts

@@ -2,7 +2,7 @@ import * as fs from 'mz/fs'
 import slugify from 'slugify'
 
 import { Injectable } from '@angular/core'
-import { HostAppService, Platform, isWindowsBuild, WIN_BUILD_WSL_EXE_DISTRO_FLAG } from 'tabby-core'
+import { HostAppService, Platform, isWindowsBuild, WIN_BUILD_WSL_EXE_DISTRO_FLAG, WIN_BUILD_WSL_EXE_CD_FLAG } from 'tabby-core'
 
 import { ShellProvider, Shell } from 'tabby-local'
 
@@ -63,6 +63,11 @@ export class WSLShellProvider extends ShellProvider {
         const lxss = wnr.getRegistryKey(wnr.HK.CU, lxssPath)
         const shells: Shell[] = []
 
+        // WSL only honors `--cd` for Linux-style paths (e.g. `~`) starting with this build.
+        // On older builds, omit it and fall back to the previous (native cwd inheritance) behavior.
+        // https://github.com/microsoft/terminal/blob/main/src/cascadia/TerminalSettingsModel/WslDistroGenerator.cpp
+        const homeDirArgs = isWindowsBuild(WIN_BUILD_WSL_EXE_CD_FLAG) ? ['--cd', '~'] : undefined
+
         if (lxss?.DefaultDistribution) {
             const defaultDistKey = wnr.getRegistryKey(wnr.HK.CU, lxssPath + '\\' + String(lxss.DefaultDistribution.value))
             if (defaultDistKey?.DistributionName) {
@@ -71,6 +76,7 @@ export class WSLShellProvider extends ShellProvider {
                     id: 'wsl',
                     name: 'WSL / Default distro',
                     command: wslPath,
+                    homeDirArgs,
                     env: {
                         TERM: 'xterm-color',
                         COLORTERM: 'truecolor',
@@ -114,6 +120,7 @@ export class WSLShellProvider extends ShellProvider {
                 name: `WSL / ${name}`,
                 command: wslPath,
                 args: ['-d', name],
+                homeDirArgs,
                 fsBase,
                 env: {
                     TERM: 'xterm-color',

tabby-local/src/api.ts

@@ -17,6 +17,13 @@ export interface Shell {
 
     cwd?: string
 
+    /**
+     * Args that make the shell start in its own home directory (e.g. WSL's `--cd ~`).
+     * Only applied when the session has no working directory of its own, since these
+     * would otherwise override it.
+     */
+    homeDirArgs?: string[]
+
     /**
      * SVG icon
      */
@@ -39,6 +46,8 @@ export interface SessionOptions {
     restoreFromPTYID: string | null
     command: string
     args: string[]
+    /** See {@link Shell.homeDirArgs} */
+    homeDirArgs: string[]
     cwd: string | null
     env: Record<string, string>
     width: number | null

tabby-local/src/profiles.ts

@@ -16,6 +16,7 @@ export class LocalProfilesService extends ProfileProvider<LocalProfile> {
             restoreFromPTYID: null,
             command: '',
             args: [],
+            homeDirArgs: [],
             cwd: null,
             env: {
                 __nonStructural: true,
@@ -82,6 +83,7 @@ export class LocalProfilesService extends ProfileProvider<LocalProfile> {
             ...this.configDefaults.options,
             command: shell.command,
             args: shell.args ?? [],
+            homeDirArgs: shell.homeDirArgs ?? [],
             env: shell.env,
             cwd: shell.cwd ?? null,
             shellType: shell.shellType ?? null,

tabby-local/src/session.ts

@@ -7,6 +7,17 @@ import { getEnvironment, substituteEnv } from './environment'
 import { resolveGuestCWD } from './wslPath'
 import { isDirectory, isDirectorySync } from './util'
 
+function usableCWD (path?: string|null): string|undefined {
+    if (!path) {
+        return undefined
+    }
+    if (!isDirectorySync(path)) {
+        console.warn('Ignoring invalid CWD:', path)
+        return undefined
+    }
+    return path
+}
+
 const windowsDirectoryRegex = /([a-zA-Z]:[^\:\[\]\?\"\<\>\|]+)/mi
 
 function mergeEnv (...envs) {
@@ -87,16 +98,18 @@ export class Session extends BaseSession {
                 })
             }
 
-            // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
-            let cwd = resolveGuestCWD(options.cwd, options.fsBase) || process.env.HOME
+            // resolveGuestCWD maps a POSIX cwd reported by a guest shell (WSL) onto its
+            // Windows-visible path before we validate it.
+            const explicitCWD = usableCWD(resolveGuestCWD(options.cwd, options.fsBase))
 
-            if (!isDirectorySync(cwd)) {
-                console.warn('Ignoring invalid CWD:', cwd)
-                cwd = undefined
-            }
+            // A shell that knows how to start in its own home directory (WSL's `--cd ~`) only gets
+            // to do so when we have no working directory for it - those args outrank the cwd below.
+            const args = explicitCWD ? options.args : [...options.args, ...options.homeDirArgs]
+
+            const cwd = explicitCWD ?? usableCWD(process.env.HOME)
 
             try {
-                pty = await this.ptyInterface.spawn(options.command, options.args, {
+                pty = await this.ptyInterface.spawn(options.command, args, {
                     name: 'xterm-256color',
                     cols: options.width ?? 80,
                     rows: options.height ?? 30,