Technically, this change is not needed, but it hopefully makes the dumped YAML a bit more readable and avoids confusion.

Thank you @xabbuh.

Thank you very much for fixing the issue, but I do want to comment out how you've said "this change is not needed".

When we go to parse that dumped unquoted yaml string, it would break.

For instance, if the dumped ideographic string was there without quotes like this:

foo: 　

Then we'd see an exception like this:

Unable to parse at line 20 (near "foo: 　").

It appears to only throw that exception if the only thing there is the ideological space (and optionally other whitespace). If there's a regular character in there, it works fine. (Here there's bar then the unicode space)

foo: bar　

I don't know if this warrants a bug report, but I thought it was at least worth mentioning. Thanks again for the quick fix!

Thanks for the feedback. This indeed looks like a bug in the parser to me. I am going to look into it.

@jasonvarga Can you confirm that #39787 fixes this as well?

Seems good!