While trying to track down why I still keep getting some random "extra" triangles
showing up when reloading files with fills, I noticed that there's an index mismatch
here that may cause problems in some rare cases:
There are "gps->totpoints" items in tmp_triangles, but there should only be
"gps->tot_triangles" triangles in the gps->triangles array. If for whatever reason
some of the triangles in tmp_triangles are invalid, this could have meant that
while a tmp_triangles candidate was skipped, a corresponding slot for a valid
triangle also got skipped.