Ticket #4799: quick fix for the visible problem (other cases might still need to be checked)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@38035 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#4228 fixed

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@38036 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e