6bfd88ac first changed the way that the GL viewport rendered the normal map to more accurately reflect object / world space rather than the current view.

There was a use case for this behavior, being able to apply a generic .jpg image as a matcap with input in viewspace.

this patch re-implements the view space behavior as another option to the normal map node. Tested release build on Win 7, MSVC 2015; below is screencap of the matcap material working again.

Here's a .blend file to test (anything after 6bfd88ac -> changing to any other space option makes it static):

This is my first C patch, so if there are any other places where changes are needed, advice is welcome :)