gdk-pixbuf uses temporary files when loading xpm images

io-xpm.c:gdk_pixbuf__xpm_image_begin_load() has the following comment:

/*
 * FIXME xpm loading progressively is not properly implemented.
 * Instead we will buffer to a file then load that file when done.
 * This is very broken but it should be relayively simple to fix
 * in the future.
 */

What this actually means is that gdk creates a file in /tmp, writes to it, and then deletes it *every* time you do any of the following in a gnome/Unity environment:

- click a mouse button anywhere (any app, any window)
- scroll a mouse wheel anywhere (any app, any window)

Additionally, if you move your mouse to top-left or bottom-right of the screen *and just hold it there*, files will be created, modified and then deleted continuously.

Clearly, this is a nasty hack and temporary files are evil at the best of times. If you have slow disks, your desktop experience may also suffer.

Temp files are created using g_file_open_tmp():

fd = g_file_open_tmp ("gdkpixbuf-xpm-tmp.XXXXXX", &context->tempname, NULL);

This template expands to file names like "/tmp/gdkpixbuf-xpm-tmp.UV9WUV".

Pressing the Windows/meta button to get the Unity search box to appear generates approximately 60 temporary files (!!)