When I open a PDF files in iceweasel or thunar, gimp is used by default. Of course, this does not make much sense. Evince or any other PDF reader should be used. (I'm not sure, whether this is related to #522998, but xfce doesn't use libgnomevfs, right?)
gnomevfs doesn't exist anymore but it's definitely the same issue. Now I don't think anyone would like gimp to be the first choice to open pdf, so I don't get why the bugs has been closed. I'm not yet forcemerging, but it still puzzles me on why (basically) everybody would need to override those defaults when they just don't make sense. Regards,
This is not a XFCE related bug, but rather MIME or local settings. Try to create file "~/.local/share/applications/defaults.list" which contains [Default Applications] application/pdf=evince.desktop or add that line if file/section exists. I guess you wish to have evince as an opener for pdf. I think that bug should be closed.
It looks like XFCE 4.10 includes a MIME type editor[1], which should help in this situation [1] http://www.xfce.org/about/tour
With Xfce4 4.10.1 (Jessie) the problem is still present. I still have to use the use the workaround suggested by Aliaksei Sheshka. It's not a big problem, but one of the many small usability issues that make Debian hard to use for most people.