repoview: split _gethiddenblockers
Split up _gethiddenblockers into two categories: (1) "static' blockers
that solely rely on the contents of obstore and are visible children of
hidden changsets. (2) "dynamic" blockers, appearing by having wd parents,
bookmarks or tags pointing to hidden changesets.
We assume that (1) doesn't change often and can be easily cached with a good
invalidation strategy. (2) change often, but barely produce blockers, so we
can recompute them if necessary.
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present