If I have a bitmap font enabled in the appearance preferences window, such as "profont", opening the behaviour tab of the Thunar preferences window will crash that Thunar instance, closing the window and producing the following terminal output: thunar: cairo-scaled-font.c:459: _cairo_scaled_glyph_page_destroy: Assertion `!scaled_font->cache_frozen' failed. Aborted (core dumped) Changing to a normal font, such as DejaVu Sans works fine and allows me to change the settings. No other settings tabs, or sections of the program that I've used have crashed with the bitmap font, only the "Behaviour" tab. This bug occurs in Thunar 1.6.4, which I couldn't specify on the bug report form as it doesn't appear on the list.
Having just had a look at the code, we don't do anything else than use normal pango attributes. I suspect this is a bug in Pango rather than Thunar. I'm contacting them for comments.
I just realised that there are other problems I can explain using this bug. Certain panel applets will crash if right clicked while a bitmap font is chosen. Mostly those not installed by default along with xfce, such as "mac menu," but also the notification area applet which both behave just like the behaviour tab of Thunar (instant crash once it tries to display whatever it is that's causing the crash.) I think that clarifies that it's not actually a Thunar issue at all, but whatever common element these things share. I'm yet to find any other instances of this bug. Were you able to reproduce it? It could be something to do with my particular setup (I just reinstalled Arch from scratch, and I don't think I had this issue before (not that I'd have noticed if this is at all a recent issue, since I don't tinker with my settings often..)
I was able to reproduce it with Dina and ProFont, yes. Problem is I don't see any way to fix this in Thunar, other than detecting that you're using a bitmap font and not touching it. This'd be complicated enough to do across all of Xfce code that I believe Pango must have a way of managing this instead of us. I'm waiting to hear from them now.
Closing invalid, as this does not seem to be a bug in thunar. Reopen if necessary.
I just wanted to report this bug using Terminus font. This makes linux not very trustworthy for the common user. Please try to fix that.