bundlerepo: basic bundle2 support
For bundlerepo to work with bundle2 files, we need to find the part that
contains the bundle's changegroup data and work with that instead of the
entire bundle. Future work can add separate processing for other bundle2
parts.
$ hg init
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ ls
a
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
B should disappear
$ ls
a