XkbFreeGeomRows - Man Page
Free rows in a section
void XkbFreeGeomRows (XkbSectionPtr section, int first, int count, Bool free_all);
section in which rows should be freed
first row to be freed
number of rows to be freed
True => all rows are freed
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.
If free_all is True, all rows are freed regardless of the value of first and count. Otherwise, the number of rows specified by count are freed, beginning with the row specified by first in the specified section.
The XkbFreeGeomRows function returns Success when there are no allocation or argument errors.
Unable to allocate storage
An argument is out of range