discovery: only calculate closed branches if required
The number of new closed branches is required for printing in error message. So
let's only calculate them if we need to print error about new branches.
Differential Revision: https://phab.mercurial-scm.org/D6314
test sparse
$ cat >> $HGRCPATH << EOF
> [ui]
> ssh = "$PYTHON" "$RUNTESTDIR/dummyssh"
> username = nobody <no.reply@fb.com>
> [extensions]
> sparse=
> purge=
> strip=
> rebase=
> EOF
$ hg init myrepo
$ cd myrepo
$ echo a > index.html
$ echo x > data.py
$ echo z > readme.txt
$ cat > webpage.sparse <<EOF
> [include]
> *.html
> EOF
$ cat > backend.sparse <<EOF
> [include]
> *.py
> EOF
$ hg ci -Aqm 'initial'
$ cd ..
Verify local clone with a sparse profile works
$ hg clone --enable-profile webpage.sparse myrepo clone1
updating to branch default
warning: sparse profile 'webpage.sparse' not found in rev 000000000000 - ignoring it
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd clone1
$ ls
index.html
$ cd ..
Verify local clone with include works
$ hg clone --include *.sparse myrepo clone2
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd clone2
$ ls
backend.sparse
webpage.sparse
$ cd ..
Verify local clone with exclude works
$ hg clone --exclude data.py myrepo clone3
updating to branch default
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd clone3
$ ls
backend.sparse
index.html
readme.txt
webpage.sparse
$ cd ..
Verify sparse clone profile over ssh works
$ hg clone -q --enable-profile webpage.sparse ssh://user@dummy/myrepo clone4
warning: sparse profile 'webpage.sparse' not found in rev 000000000000 - ignoring it
$ cd clone4
$ ls
index.html
$ cd ..