Xkb provides a number of functions to allocate and free subcomponents of a keyboard geometry. Use these
functions to create or modify keyboard geometries. Note that these functions merely allocate space for
the new element(s), and it is up to you to fill in the values explicitly in your code. These allocation
functions increase sz_* but never touch num_* (unless there is an allocation failure, in which case they
reset both sz_* and num_* to zero). These functions return Success if they succeed, BadAlloc if they are
not able to allocate space, or BadValue if a parameter is not as expected.
XkbAllocGeomSections allocates num_needed sections and adds them to the geometry geom. No initialization
of the sections is done.
To free geometry sections, use XkbFreeGeomSections.