I finally started investigating why my Pidgin consistently leaks GDI objects such that within a day of startup it has over 6,000 allocated.
I traced the problem to this extension by disabling all plugins, then enabling them in turn looking for the leak.
Pidgin 2.53 WinXP sp2.
The problem can be seen by opening a monitor (taskinfo, etc) on the Pidgin process, then opening a window with a contact and moving the window around the screen. Doing this for a few seconds causes several hundred GDI objects to be allocated -- and then apparently never freed.
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