Sybren, following the modification in mesh.c that was needed here, I've checked all the file and found this 3 others which could be updated about totxxx value:

• BKE_mesh_free
• BKE_mesh_copy_data
• BKE_mesh_copy

Maybe you'll want to keep all that in a separated update. So I won't propose one myself.

More explanation:

• This revision is a port of remesh modifier
• In this context, the algorithm use a octree lib which failed to run without a modifier to mesh.c
• The cause of that is totvert, totedge, totface, etc. were not assigned to by BKE_mesh_new_nomain. So I had to modify it too

The totxxx assignment is well spotted, and I've committed just that change on your behalf in bcb245bd7137a8c3df061ed349c41c2247c6ef0f.