[cairo] When printing, chars are replaced with square graphic char

Adrian Johnson ajohnson at redneon.com
Sat Sep 10 07:56:58 PDT 2011

On 10/09/11 20:21, Roger wrote:
> I forgot to mention, this only occurs when printing and not exporting to
> PS/PDF.  (I started using this as a backup plan for printing.)  This also
> further tells me it's likely not CUPS/LPR related and probably a few other
> packages can be omitted from speculation.

If PS/PDF produced by cairo is correct in a viewer then there are two
possibilities. As ghostscript is usually more tolerant of bad PS than
most printers it could be a bug in the cairo font subsetting that
triggers the problem on your printer but works fine with ghostscript. To
debug this requires trying different fonts and text to trying to find a
what combinations of fonts and text triggers the bug.

Or it could be caused by any of the filtering CUPS does. Assuming it is
a PS printer you can check this by bypassing CUPS and printing the PS
file directly with "lpr -o raw". You can also capture the data sent
directly to the printer and check if it views correctly with
ghostscript. The steps to do this are:

1. Run "cupsctl FileDevice=yes"
2. Clone your printer. I don't use Gentoo but in Ubuntu in
system-config-printer you right click the printer and select Duplicate.
3. Run "lpadmin -p myprinter -E -v file:/tmp/printout"
   replace myprinter with the name of your cloned printer.
4. Print to the cloned printer. The captured output will be in /tmp/printout

> I would be happy to scan in my printed output or send it via
> SnailMail. ;-)

I would prefer to receive a copy of the PS file. Preferably the smallest
test case you can generate that triggers the bug.

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