fix: preserve unicode in Windows clipboard fallback

src/ink/termio/osc.test.ts

@@ -0,0 +1,110 @@
+import { afterEach, beforeEach, describe, expect, mock, test } from 'bun:test'
+
+const originalEnv = { ...process.env }
+const originalPlatform = process.platform
+
+const execFileNoThrowMock = mock(
+  async () => ({ code: 0, stdout: '', stderr: '' }),
+)
+
+mock.module('../../utils/execFileNoThrow.js', () => ({
+  execFileNoThrow: execFileNoThrowMock,
+}))
+
+async function importFreshOscModule() {
+  return import(`./osc.ts?ts=${Date.now()}-${Math.random()}`)
+}
+
+describe('Windows clipboard fallback', () => {
+  beforeEach(() => {
+    execFileNoThrowMock.mockClear()
+    process.env = { ...originalEnv }
+    delete process.env['SSH_CONNECTION']
+    delete process.env['TMUX']
+    Object.defineProperty(process, 'platform', { value: 'win32' })
+  })
+
+  afterEach(() => {
+    mock.restore()
+    process.env = { ...originalEnv }
+    Object.defineProperty(process, 'platform', { value: originalPlatform })
+  })
+
+  test('uses PowerShell instead of clip.exe for local Windows copy', async () => {
+    const { setClipboard } = await importFreshOscModule()
+
+    await setClipboard('Привет мир')
+
+    expect(execFileNoThrowMock.mock.calls.some(([cmd]) => cmd === 'clip')).toBe(
+      false,
+    )
+    expect(
+      execFileNoThrowMock.mock.calls.some(([cmd]) => cmd === 'powershell'),
+    ).toBe(true)
+  })
+
+  test('passes the original Unicode text to the Windows copy command', async () => {
+    const { setClipboard } = await importFreshOscModule()
+
+    await setClipboard('Привет мир')
+
+    const windowsCall = execFileNoThrowMock.mock.calls.find(
+      ([cmd]) => cmd === 'powershell',
+    )
+
+    expect(windowsCall?.[2]).toMatchObject({ input: 'Привет мир' })
+  })
+})
+
+describe('clipboard path behavior remains stable', () => {
+  beforeEach(() => {
+    execFileNoThrowMock.mockClear()
+    process.env = { ...originalEnv }
+    delete process.env['SSH_CONNECTION']
+    delete process.env['TMUX']
+  })
+
+  afterEach(() => {
+    mock.restore()
+    process.env = { ...originalEnv }
+    Object.defineProperty(process, 'platform', { value: originalPlatform })
+  })
+
+  test('getClipboardPath stays native on local macOS', async () => {
+    Object.defineProperty(process, 'platform', { value: 'darwin' })
+    const { getClipboardPath } = await importFreshOscModule()
+
+    expect(getClipboardPath()).toBe('native')
+  })
+
+  test('getClipboardPath stays tmux-buffer when TMUX is set', async () => {
+    Object.defineProperty(process, 'platform', { value: 'linux' })
+    process.env['TMUX'] = '/tmp/tmux-1000/default,123,0'
+    const { getClipboardPath } = await importFreshOscModule()
+
+    expect(getClipboardPath()).toBe('tmux-buffer')
+  })
+
+  test('Windows clipboard fallback is skipped over SSH', async () => {
+    Object.defineProperty(process, 'platform', { value: 'win32' })
+    process.env['SSH_CONNECTION'] = '1 2 3 4'
+    const { setClipboard } = await importFreshOscModule()
+
+    await setClipboard('Привет мир')
+
+    expect(execFileNoThrowMock.mock.calls.some(([cmd]) => cmd === 'powershell')).toBe(
+      false,
+    )
+  })
+
+  test('local macOS clipboard fallback still uses pbcopy', async () => {
+    Object.defineProperty(process, 'platform', { value: 'darwin' })
+    const { setClipboard } = await importFreshOscModule()
+
+    await setClipboard('hello')
+
+    expect(execFileNoThrowMock.mock.calls.some(([cmd]) => cmd === 'pbcopy')).toBe(
+      true,
+    )
+  })
+})

src/ink/termio/osc.ts

@@ -129,7 +129,7 @@ export async function tmuxLoadBuffer(text: string): Promise<boolean> {
  * Local (no SSH_CONNECTION): also shell out to a native clipboard utility.
  * OSC 52 and tmux -w both depend on terminal settings — iTerm2 disables
  * OSC 52 by default, VS Code shows a permission prompt on first use. Native
- * utilities (pbcopy/wl-copy/xclip/xsel/clip.exe) always work locally. Over
+ * utilities (pbcopy/wl-copy/xclip/xsel/PowerShell Set-Clipboard) always work locally. Over
  * SSH these would write to the remote clipboard — OSC 52 is the right path there.
  *
  * Returns the sequence for the caller to write to stdout (raw OSC 52
@@ -211,9 +211,18 @@ function copyNative(text: string): void {
       return
     }
     case 'win32':
-      // clip.exe is always available on Windows. Unicode handling is
-      // imperfect (system locale encoding) but good enough for a fallback.
-      void execFileNoThrow('clip', [], opts)
+      // PowerShell's Set-Clipboard preserves Unicode text more reliably than
+      // clip.exe, which can mangle non-ASCII text under some Windows locales.
+      void execFileNoThrow(
+        'powershell',
+        [
+          '-NoProfile',
+          '-NonInteractive',
+          '-Command',
+          '$text = [Console]::In.ReadToEnd(); Set-Clipboard -Value $text',
+        ],
+        opts,
+      )
       return
   }
 }