manifest: add some documentation to _lazymanifest python code
It was not particularly easy figuring out the design of this class and keeping
track of how the pieces work. So might as well write some of it down for the
next person.
test sparse
$ hg init myrepo
$ cd myrepo
$ cat >> $HGRCPATH <<EOF
> [extensions]
> sparse=
> purge=
> strip=
> rebase=
> EOF
$ echo a > index.html
$ echo x > data.py
$ echo z > readme.txt
$ cat > base.sparse <<EOF
> [include]
> *.sparse
> EOF
$ hg ci -Aqm 'initial'
$ cat > webpage.sparse <<EOF
> %include base.sparse
> [include]
> *.html
> EOF
$ hg ci -Aqm 'initial'
Clear rules when there are includes
$ hg debugsparse --include *.py
$ ls
data.py
$ hg debugsparse --clear-rules
$ ls
base.sparse
data.py
index.html
readme.txt
webpage.sparse
Clear rules when there are excludes
$ hg debugsparse --exclude *.sparse
$ ls
data.py
index.html
readme.txt
$ hg debugsparse --clear-rules
$ ls
base.sparse
data.py
index.html
readme.txt
webpage.sparse
Clearing rules should not alter profiles
$ hg debugsparse --enable-profile webpage.sparse
$ ls
base.sparse
index.html
webpage.sparse
$ hg debugsparse --include *.py
$ ls
base.sparse
data.py
index.html
webpage.sparse
$ hg debugsparse --clear-rules
$ ls
base.sparse
index.html
webpage.sparse