Hi,


while trying out the new version of ConTeXt LMTX (2024.06.14 09:18) I 
encountered some problems related to the PDF output files.

First, I tried to print a single page of the excellent new math manual 
(many thanks to everyone involved in creating it, it’s great for 
beginners like me and surely for experienced users too), but I noticed 
that all of the extensibles in the formulas (like the bar in \frac, 
\sqrt, long integral signs, and probably more) have disappeared. 
Everything else was printed correctly.

After investigating, I found out that Okular on Linux converts the PDF 
file to PostScript before printing (at least on my system), and I was 
able to replicate this behavior by converting it manually to PostScript 
with Poppler (pdftops in.pdf out.ps) or Ghostscript (pdf2ps in.pdf out.ps).

Printing from Firefox was not affected for me as it did not convert to 
PostScript.

I was unable to reproduce this with my own documents (created with 
ConTeXt LMTX 2024.05.31 18:50), so I decided to try this with the new 
version. And with it, that was indeed reproducible.

To ensure that this is the PDF’s fault, I decided to try this on Windows 
with Adobe Acrobat Reader on a different Computer with another fresh 
installation of ConTeXt. But it wasn’t any better:

Adobe Acrobat Reader displayed two different error messages when trying 
to scroll through or zoom in on the math manual:
1. “An error exists on this page. Acrobat may not display the page 
correctly. Please contact the person who created the PDF document to 
correct the problem.”
2. “There was an error processing a page. A number is out of range.”
Sometimes the first one is shown, sometimes the second one.

Additionally, some parts of the manual were blank (they were displayed 
correctly in Okular, Firefox, and many more viewers), I suspect those 
who contain extensibles in formulas. Following example leads to the same 
behaviour:

\setuppapersize[S33]    % Just to make page smaller
\setupbodyfont[modern, 11pt]
\starttext
Hello.
\startformula
\frac{a^2 + b^2}{1} = c^2
\stopformula
\page
Hello.
\startformula
a^2 + b^2 = c^2
\stopformula
\stoptext

The first page is empty in Acrobat Reader, whereas it’s displayed 
correctly in all other PDF viewers I tried. But again, when converting 
to PostScript, the fraction bar vanishes. The second page is fine.

I attached the faulty example.pdf file and some screenshots of it opened 
in different PDF viewers, and of the math manual. The screenshot of the 
math manual opened in Acrobat Reader shows that the second half of the 
page is completely gone. example_pdftops-ps2pdf.pdf is example.pdf 
converted to PostScript with Poppler and then converted to PDF again 
with Ghostscript (attaching the PostScript file isn’t possible because 
of file size). Opened in Okular or other Poppler based viewers you’ll 
see a dot instead of the fraction bar (which gets infinitely smaller 
while zooming-in), and openend in Firefox, MuPDF or Acrobat Reader 
you’ll see a cut off bar.

One last thing, for some reason “\italiansqrt” on page 52 of the math 
manual is converted perfectly fine to PostScript (at least it looks right).

Please let me know if you would like me to provide more information.


Best,
Ralph