<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Assertion "(_cairo_atomic_int_get (&(&surface->ref_count)->ref_count) > 0)"" href="https://bugs.freedesktop.org/show_bug.cgi?id=91967#c27">Comment # 27</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Assertion "(_cairo_atomic_int_get (&(&surface->ref_count)->ref_count) > 0)"" href="https://bugs.freedesktop.org/show_bug.cgi?id=91967">bug 91967</a> from <a class="email" href="mailto:jskarvad@redhat.com" title="Jaroslav Škarvada <jskarvad@redhat.com>"> Jaroslav Škarvada</a> <pre>(In reply to Alberts Muktupāvels from <a href="show_bug.cgi?id=91967#c26">comment #26</a>) > (In reply to Jaroslav Škarvada from <a href="show_bug.cgi?id=91967#c25">comment #25</a>) > > (In reply to Alberts Muktupāvels from <a href="show_bug.cgi?id=91967#c24">comment #24</a>) > > > (In reply to Jaroslav Škarvada from <a href="show_bug.cgi?id=91967#c23">comment #23</a>) > > > > But I think the proposed fix is dirty. It relies on the safety check inside > > > > the cairo_surface_destroy. Cleanly written code shouldn't do this. The > > > > control flow should never get into the cairo_surface_destroy for the second > > > > time, that's why I wrote "maybe there is a better fix". But this is > > > > definitely question for the upstream maintainers. > > > > > > I don't want to agree on this. > > > > > > Check what could happen if it is called this way: > > > _get_image_surface (..., ..., FALSE); > > > > > > I am too lazy to count, but there are definitely multiple paths that could > > > end up calling cairo_surface_destroy (&image->base); when image is still > > > NULL. > > > > > > Think about this way - setting it to NULL after destroying is same as if > > > that function would have been called with try_shm = FALSE. > > > > See it this way: > > > > - what about setting the surface NULL in the cairo_surface_destroy after > > destroying it? It will fix all these issues, but it is apparently not the > > right way how to fix such bugs. > > > > I think that all the wrong paths leading to the second call of the > > cairo_surface_destroy should be fixed/cleaned. But I am not upstream, so > > it's irrelevant what I am thinking about it. > > When try_shm == FALSE then cairo_surface_destroy still can be called when > image == NULL and it will be first call... > > Safety check in cairo_surface_destroy most likely is to save code / lines. > It is easier to write simply cairo_surface_destory (surface); then if > (surface) cairo_surface_destroy (surface); > > Since cairo_surface_destroy is created NULL safe the problem is not that it > is called second time. Problem is that it is called with already destroyed > surface. I am afraid you don't understand what I tried to express. And I am also afraid that just repeating arguments will not move this bugzilla further. For upstream maintainers: there are backtraces, reproducer and clear insight what's going there. Could you take a look?</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>