patch [#34103] check_for_dupid.patch
from Lawrence D'Oliveiro (ldo)

- more comments
- more uses of bool type
- define symbol for length of in_use array in check_for_dupid


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@55150 954f8c5b-7b00-dc11-b283-0030488c597c