Re: Garbage copied from PDF when using certain fonts

[Masamichi Hosoda]

>>> When using certain fonts (in my case, Noto CJK, both pan-CJK and
>>> subset versions), the output looks right but when copied from the
>>> generated PDF file, everything becomes garbage.  [...]
>>
>> The problem does not appear if the cairo backend is used, see
>> https://gitlab.com/lilypond/lilypond/-/merge_requests/853.
> 
> This is good news!

When copying and pasting from a PDF generated using cairo backend,
some characters turned into similar but different characters.
The characters are garbled in both AJ1 and AI0 fonts.
If you use ps backend, characters by the AJ1 font are not garbled.

```
\version "2.22.0"
\markup {
  \override #'(font-name . "Noto Serif CJK JP") % Adobe-Identity-0 (AI0) font
  { 初見はハ長調で高音の白玉があった }
  \override #'(font-name . "HaranoAjiMincho") % Adobe-Japan1 (AJ1) font
  { 初見はハ長調で高音の白玉があった }
}
```

.ly file  -> Copied and pasted from PDF generated using cairo backend
見 U+898B -> U+2F92
長 U+9577 -> U+2ED1
高 U+9AD8 -> U+2FBC
音 U+97F3 -> U+2FB3
白 U+767D -> U+2F69
玉 U+7389 -> U+2F5F