Description of problem: http://www.redhat.com/docs/manuals/dir-server/plugin/7.1/function.htm#1113969 documents slapi_vattr_value_compare() as storing the value 0 if the value being compared is equal, and 1 if it isn't, but the directory server appears to store 1 if the values are equal, and 0 if they aren't.
I updated the 7.1 plugin guide so that the success value is 1 and for fail is 0. This is live on rh.com: http://www.redhat.com/docs/manuals/dir-server/plugin/7.1/function.htm#1113969 I also updated the 8.x draft docs. Closing the bug.