Able to write to read-only pdf files

[Adriano Vilela Barbosa <adriano.vilela@gmail.com>]

Hello,

Yesterday I came across a very weird behavior while annotating a pdf
file in Okular. Long story short: I opened a read-only pdf file
(permissions: 400), inserted some comments and hit the save button. At
this point, I thought I had been working on a write-enabled copy of
the file. After a while, I realized that I was actually working on the
read-only version of the file, that somehow got saved to disk when I
hit the save icon. Okular was not only able to save the file to disk,
but the file permissions were changed to 644.

I initially thought this was an Okular problem. However, after some
more testing, I was able to reproduce the problem with Xournal. This
makes me think that the problem is not with Okular or Xournal, but
with some common library used by both of these packages (maybe
libpoppler?).

Has anybody had this problem? Can anybody reproduce it?

I'm using Debian testing.

Thanks a lot,

Adriano