fix(windows): configure stdio as utf-8

src/kimi_cli/__main__.py

@@ -5,11 +5,37 @@
 from pathlib import Path
 
 
+def _ensure_utf8_stdio() -> None:
+    """Use UTF-8 for the standard Windows text streams when they support it.
+
+    Git Bash may expose the Windows legacy code page (for example, cp936) to
+    Python.  The interactive UI contains characters outside those code pages,
+    so Rich can otherwise fail while rendering the welcome panel.  Redirected
+    and non-standard streams are deliberately left alone.
+    """
+    if sys.platform != "win32":
+        return
+
+    for stream_name in ("stdout", "stderr"):
+        stream = getattr(sys, stream_name)
+        reconfigure = getattr(stream, "reconfigure", None)
+        if not callable(reconfigure):
+            continue
+        try:
+            reconfigure(encoding="utf-8", errors="replace")
+        except (OSError, TypeError, ValueError):
+            # Some embedders expose text-like streams with a partial or locked
+            # reconfigure implementation. Preserve those streams as-is.
+            continue
+
+
 def _prog_name() -> str:
     return Path(sys.argv[0]).name or "kimi"
 
 
 def main(argv: Sequence[str] | None = None) -> int | str | None:
+    _ensure_utf8_stdio()
+
     from kimi_cli.telemetry.crash import install_crash_handlers, set_phase
     from kimi_cli.utils.proxy import normalize_proxy_env
 

tests/core/test_windows_stdio.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import io
+import sys
+
+
+class _EncodinglessStream:
+    encoding = None
+
+    def __init__(self) -> None:
+        self.value = ""
+
+    def write(self, value: str) -> int:
+        self.value += value
+        return len(value)
+
+    def flush(self) -> None:
+        pass
+
+
+def test_windows_stdio_allows_welcome_rendering_with_cp936_streams(monkeypatch) -> None:
+    from kimi_cli.__main__ import _ensure_utf8_stdio
+
+    stdout_buffer = io.BytesIO()
+    stderr_buffer = io.BytesIO()
+    stdout = io.TextIOWrapper(stdout_buffer, encoding="cp936", errors="strict")
+    stderr = io.TextIOWrapper(stderr_buffer, encoding="cp936", errors="strict")
+    monkeypatch.setattr(sys, "platform", "win32")
+    monkeypatch.setattr(sys, "stdout", stdout)
+    monkeypatch.setattr(sys, "stderr", stderr)
+
+    _ensure_utf8_stdio()
+
+    import kimi_cli.ui.shell as shell_ui
+    from kimi_cli.ui.shell import _print_welcome_info
+    from kimi_cli.ui.shell.console import _KimiConsole
+
+    monkeypatch.setattr(shell_ui, "console", _KimiConsole(file=sys.stdout, highlight=False))
+    _print_welcome_info("Kimi Code CLI", [])
+    sys.stdout.flush()
+
+    assert sys.stdout.encoding == "utf-8"
+    assert "Welcome to Kimi Code CLI!" in stdout_buffer.getvalue().decode("utf-8")
+
+
+def test_windows_stdio_preserves_redirected_and_encodingless_streams(monkeypatch) -> None:
+    from kimi_cli.__main__ import _ensure_utf8_stdio
+
+    redirected = io.StringIO()
+    encodingless = _EncodinglessStream()
+    monkeypatch.setattr(sys, "platform", "win32")
+    monkeypatch.setattr(sys, "stdout", redirected)
+    monkeypatch.setattr(sys, "stderr", encodingless)
+
+    _ensure_utf8_stdio()
+
+    assert sys.stdout is redirected
+    assert sys.stderr is encodingless
+    print("redirected")
+    print("encodingless", file=sys.stderr)
+    assert redirected.getvalue() == "redirected\n"
+    assert encodingless.value == "encodingless\n"
+
+
+def test_non_windows_stdio_is_unchanged(monkeypatch) -> None:
+    from kimi_cli.__main__ import _ensure_utf8_stdio
+
+    stream = io.TextIOWrapper(io.BytesIO(), encoding="cp936", errors="strict")
+    monkeypatch.setattr(sys, "platform", "linux")
+    monkeypatch.setattr(sys, "stdout", stream)
+
+    _ensure_utf8_stdio()
+
+    assert sys.stdout is stream
+    assert sys.stdout.encoding == "cp936"