Like the normal dri i915 driver, the gallium i915 driver still suffers from broken viewport handling. For the full discussion and the fix for the i915 driver, see:

http://bugs.freedesktop.org/show_bug.cgi?id=20473

(This bug also talks about tiling issues. This is all fixed - it was an independent kernel/drm issue) 

Summary:
- steps to reproduce: fire up glxgears (with LIBGL_DRIVERS_PATH=lib/gallium)  and resize the window. It looks like the rendering area does not get updated - if the window is wider than the original size, the additional area stays black. Furthermore when the height of the window is changed, the gears move downward out of the window and a black border starts to appear on the top.

- the gallium driver was broken after the normal dri driver was already broken (unfortunately I don't know an exact revision range anymore). According to my comments, gallium from the master branch was working on around 2009-04-07, but broken from 2009-05-09 onwards.

I've assigned the bug to "Other" because there is no gallium component.