strange space width jumping in header lines

[Werner LEMBERG]

[texinfo.tex version 2022-09-15.17]


I noticed that for unknown reasons the space width between
'Chapter X:' and the following text in the header line varies; see
attached images.  Unfortunately, I can't see any logic behind it,
which makes it hard for me to provide a minimum example.

This seems to be an older bug; I've tested with version 2022-04-10.11,
and I get the same issue – apparently, spacing changes (for whatever
reason) in the textblock leak into the header line.

It might also manifest because we use some extra code to replace CM
typewriter with LMMonoLt10 – for the LilyPond documentation we need
both a bold and a bold slanted typewriter face to have proper pygments
support within LilyPond code snippets.

  
https://gitlab.com/lilypond/lilypond/-/blob/master/Documentation/en/common-macros.itexi#L634

And yes, I walked the extra mile to set up OT1 encoding for these
fonts :-)

  
https://gitlab.com/lilypond/lilypond/-/blob/master/Documentation/tex/lm-ot1-map.tex
  
https://gitlab.com/lilypond/lilypond/-/blob/master/Documentation/tex/lm-ot1.tex

I hope this helps you find the problem; otherwise please tell me what
I should provide next.


    Werner