mergestate: implement unresolvedcount() in terms of unresolved()
This simplifies the method slightly. It does create a full list of
paths while doing so, but it's not a lot of data anyway (besides, I
would think references to strings are no larger than (references to?)
True).
#require symlink
https://bz.mercurial-scm.org/1438
$ hg init
$ ln -s foo link
$ hg add link
$ hg ci -mbad link
$ hg rm link
$ hg ci -mok
$ hg diff -g -r 0:1 > bad.patch
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg import --no-commit bad.patch
applying bad.patch
$ hg status
R link
? bad.patch