Formatter's is_decorated property is temporarily disabled during remove_format breaking concurrent threads

[vfazio]

See python-poetry/poetry#9334

Poetry relies on the formatter's is_decorated property to be consistent when multiple threads query the property.

If one thread is in the middle of updating a section and has changed the formatter's is_decorated property via remove_format, a second thread may query it and get back an incorrect result.

If cleo is not thread-safe, the developers of poetry should be made aware, otherwise there may need to be changes to how remove_format and format work in relation to whether decorated output is supported in general vs decorated output is being emitted for the current format operation.

[vfazio]

Note that this seems to be an issue because the Formatter object is a shared instance across the IO objects, in Poetry's case StreamOutput and child SectionOutput objects (see StreamOutput.section)

One "workaround" would be to duplicate the Formatter object instead of sharing the object. That way the StreamOutput object could query its Formatter object independent of what the SectionOutput objects are using. This would allow the sections to manipulate their formatters independently and existing code may "just work" without having to make:

Formatter.remove_format -> Formatter.format -> Formatter.format_and_wrap -> Formatter._apply_current_style

aware that while the formatter supports decorating, this operation should not be decorated.

If that's not ideal because formatter styles need to be kept in sync between the parent output object and child sections, maybe leverage a different private instance flag:

    def remove_format(self, text: str) -> str:
        self._suppress_decoration = True
        text = re.sub(r"\033\[[^m]*m", "", self.format(text))
        self._suppress_decoration = False

        return text

    def _apply_current_style(
        self, text: str, current: str, width: int, current_line_length: int
    ) -> tuple[str, int]:
        if not text:
            return "", current_line_length

        if not width:
            if self.is_decorated() and not self._suppress_decoration:
                return self._style_stack.current.apply(text), current_line_length

            return text, current_line_length

</snip>
        if self.is_decorated() and not self._suppress_decoration:
            apply = self._style_stack.current.apply
            text = "\n".join(map(apply, lines))
            
        return text, current_line_length