[Tuxpaint-devel] Tux Paint & Tux Paint Config. and quotes in config file settings

[Bill K. <nb...@so...>]

On Linux/Unix, Tux Paint uses "wordexp()" to do some word
expansion of config-file arguments, e.g. you can specify

  savedir=$HOME/tuxpaint/

and it will do what you'd expect.  However, if there are
spaces, things go bonkers.  I didn't notice this myself,
because I avoid spaces in file and directory names, and
also don't really fiddle with my Tux Paint settings much!

I DID notice it once I added the new "uifont" option,
because many font family names contain spaces
(e.g., "Ubuntu Condensed", "Open Sans Condensed",
"Nimbus Sans Narrow", "Bitstream Vera Sans Mono", etc.)

So I made sure Tux Paint Config. wrapped the font name in
quotes, which worked for me on Linux because Tux Paint is
using wordexp(), but Shin-ichi quickly pointed out that
Windows does NOT use wordexp(), so Tux Paint would try
to load non-existent fonts, due to the extraneous quotes!

In experimenting, I then discovered wordexp() was being
used unsafely, and Tux Paint could CRASH (segfault!) when
trying to read a config-file setting like:

  savedir=$HOME/dir with space/

It works fine with quotes:

  savedir="$HOME/dir with space/"

So I've simply made Tux Paint Config. ALWAYS put quotes
around these settings, when writing out a config. file
(and trimming them from the start/end, when reading in
from a config. file):

  uifont
  colorfile
  savedir
  exportdir
  datadir
  printcommand
  altprintcommand

Similarly, Tux Paint itself will not only run wordexp() on Linux,
but will now also trim beginning/end quotes from ALL settings,
on ALL [other] platforms.

If there are issues, or someone has a better idea, please
speak up!  As always, please test all this on your favorite
OSes to make sure things continue to work as expected.
Thanks!

-- 
-bill!
Sent from my computer