GTK file chooser shows wrong thumbnail and filename in the preview panel on the right if file is selected by typing letters in the filenames list and then navigating up and down with arrow keys.

For example, let's say I'm browsing a folder with GTK file chooser in which I have:

 - DSC00001.jpg
 - DSC00002.jpg
 - IMG00001.jpg
 - IMG00002.jpg
 - IMG00003.jpg
 - IMG00004.jpg

I want to select and open IMG00003.jpg, so (with focus on the filenames list) I type "IM" on my keyboard to jump to IMG00001.jpg and then press the down arrow key twice in order to highlight IMG00003.jpg. IMG00003.jpg is correctly highlighted (and if I press Enter is correctly opened), but on the right of the GTK file chooser dialog, I can wrongly see preview (filename and thumbnail) for IMG00002.jpg instead.

To be sure this bug is not distribution-specific, I tested it in a clean virtual machine for:

 - Xubuntu 14.04 LTS with XFCE, using GIMP to trigger file chooser dialog
 - Xubuntu 14.04 LTS with XFCE, using Firefox to trigger file chooser dialog
 - Debian 7.7.0 Gnome, using GIMP to trigger file chooser dialog