comparison mercurial/dispatch.py @ 46173:a9765e0a461d

dispatch: gate against missing stdout/stderr

We do need procutil.stdin/stdout/stderr, but we don't care much for sys.std*.
Let's leave them be None as it is the Python 3 way.

46172:d04c0e494cfe

        # and sys.stderr. They will inherit the line ending normalization settings,
        # potentially causing e.g. \r\n to be emitted. Since emitting \n should
        # "just work," here we change the sys.* streams to disable line ending
        # normalization, ensuring compatibility with our ui type.

        # write_through is new in Python 3.7.
        kwargs = {
            "newline": "\n",
            "line_buffering": sys.stdout.line_buffering,
        }
        if util.safehasattr(sys.stdout, "write_through"):
            kwargs["write_through"] = sys.stdout.write_through
        sys.stdout = io.TextIOWrapper(
            sys.stdout.buffer, sys.stdout.encoding, sys.stdout.errors, **kwargs
        )

        kwargs = {
            "newline": "\n",
            "line_buffering": sys.stderr.line_buffering,
        }
        if util.safehasattr(sys.stderr, "write_through"):
            kwargs["write_through"] = sys.stderr.write_through
        sys.stderr = io.TextIOWrapper(
            sys.stderr.buffer, sys.stderr.encoding, sys.stderr.errors, **kwargs
        )

        if sys.stdin is not None:
            # No write_through on read-only stream.
            sys.stdin = io.TextIOWrapper(
                sys.stdin.buffer,

                line_buffering=sys.stdin.line_buffering,
            )

    def _silencestdio():
        for fp in (sys.stdout, sys.stderr):
            # Check if the file is okay
            try:
                fp.flush()
                continue
            except IOError:

46173:a9765e0a461d

        # and sys.stderr. They will inherit the line ending normalization settings,
        # potentially causing e.g. \r\n to be emitted. Since emitting \n should
        # "just work," here we change the sys.* streams to disable line ending
        # normalization, ensuring compatibility with our ui type.

        if sys.stdout is not None:
            # write_through is new in Python 3.7.
            kwargs = {
                "newline": "\n",
                "line_buffering": sys.stdout.line_buffering,
            }
            if util.safehasattr(sys.stdout, "write_through"):
                kwargs["write_through"] = sys.stdout.write_through
            sys.stdout = io.TextIOWrapper(
                sys.stdout.buffer,
                sys.stdout.encoding,
                sys.stdout.errors,
                **kwargs
            )

        if sys.stderr is not None:
            kwargs = {
                "newline": "\n",
                "line_buffering": sys.stderr.line_buffering,
            }
            if util.safehasattr(sys.stderr, "write_through"):
                kwargs["write_through"] = sys.stderr.write_through
            sys.stderr = io.TextIOWrapper(
                sys.stderr.buffer,
                sys.stderr.encoding,
                sys.stderr.errors,
                **kwargs
            )

        if sys.stdin is not None:
            # No write_through on read-only stream.
            sys.stdin = io.TextIOWrapper(
                sys.stdin.buffer,

                line_buffering=sys.stdin.line_buffering,
            )

    def _silencestdio():
        for fp in (sys.stdout, sys.stderr):
            if fp is None:
                continue
            # Check if the file is okay
            try:
                fp.flush()
                continue
            except IOError: