Created attachment 4709 chooser-dialog-monitor-height.patch This is a feature proposal, not a bug fix. It might not be to everyone's taste, but I found it useful when having to deal a lot with that dialog. There might be scenarios where these changes may not be good, but honestly I couldn't think of any. While the chooser dialog has been made resizable in 1.5.1, I found it a bit uncomfortable having to do the same adjustments manually over and over again. So why not let thunar resize the dialog window automatically to the available monitor height? This patch works fine for low and high resolutions (tested from 800x600 to 1920x1080) and should do so for multi-monitor configurations. It also increases the width of the scrolled window by about 100 pixel.
Dialogs that auto size to maximize the screen are horrible and personally I consider this dialog "hardly used".
I don't find it horrible as it doesn't really maximize, and it would have been a rather easy solution. Is this open for discussion? If so, how about saving and restoring the width and height via xfconf then, giving the user control about the resizing? Would that be too complicated?