Most projects will have their branch heads matching in all branches,
so switching between them should be just a matter of updating the
work tree's HEAD symref. This can be done in pure Python, saving
quite a bit of time over forking 'git checkout'.
Signed-off-by: Shawn O. Pearce <sop@google.com>
This is mostly useful if the number of projects to switch is many
(e.g. all of Android) and a large number of them are behind the
current manifest revision. We wind up needing to run git just to
make the working tree match, and that often makes the command take
a couple of seconds longer than we'd like.
Signed-off-by: Shawn O. Pearce <sop@google.com>
If `repo start foo` fails due to uncommitted and unmergeable changes
in a single project, we have switched half of the projects over to
the new target branches, but didn't on the one that failed to move.
This change improves the situation by doing three things differently:
- We keep going when we encounter an error, so other projects
that can successfully switch still switch.
- We ignore projects whose current branch is already on the
requested name; they are logically already setup.
- We checkout the branch if it already exists, rather than
trying to recreate the branch.
Bug: REPO-22
Signed-off-by: Shawn O. Pearce <sop@google.com>
