fix bug infinite subdivision when p = 0 in one point


git-svn-id: https://geuz.org/svn/gmsh/trunk@20129 59c8cabf-10d6-4a28-b43f-3936b85956c4
cleanup


git-svn-id: https://geuz.org/svn/gmsh/trunk@20130 59c8cabf-10d6-4a28-b43f-3936b85956c4