Fix bug in new changes code where it can be confused if the idcache is out of date.
Fix bug in new changes code where it can be confused if the idcache is
out of date.

bk: 3d88cb4dDluGTapwmvCIsRHSCjK0Ww
bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper