How to apply rhino patch:
- cvs -d :pserver:anonymous@cvs-mirror.mozilla.org:/cvsroot co -r Rhino1_6R7_BRANCH mozilla/js/rhino
- cd mozilla/js/rhino
- copy the custom_rhino.diff file to mozilla/js/rhino
- patch -p0 <custom_rhino.diff


How to generate a new patch:
- cd to mozilla/js/rhino directory created in the above steps
- cvs diff -u8p . > custom_rhino2.diff

More info here on patches:
http://developer.mozilla.org/en/docs/Creating_a_patch