This is useful when working with stacked branches, because you can now move
"pick" entries across an update-ref command and you can tell exactly which
branch the commit will end up in.
It's also useful to spot situations where the --update-refs option didn't work
as desired. For example, if you duplicate a branch and want to rebase only one
of the branches but not the other (maybe for testing); if you have
rebase.updateRefs=true in your git config, then rebasing one branch will move
the other branch along. To solve this we'll have to introduce a way to delete
the update-ref entry (maybe by hitting backspace?); this is out of scope for
this PR, so for now users will have to type "git rebase --edit-todo" into the
custom command prompt to sort this out.
We will also have to prevent users from trying to turn update-ref commands into
other commands like "pick" or "drop"; we'll do this later in this branch.
So far the algorithm worked on the assumption that the output of the "git show"
command corresponds one-to-one to the lines of the rebase-todo file. This
assumption doesn't hold once we start to include todo lines that don't have a
sha (like update-ref), or when the todo file contains multiple entries for the
same sha. This should never happen normally, but it can if users manually edit
the todo file and duplicate a line.
The main reason for doing this (besides the reasons given for Status in the
previous commit) is that it allows us to easily convert from TodoCommand to
Action and back. This will be needed later in the branch. Fortunately,
TodoCommand is one-based, so this allows us to add an ActionNone constant with
the value 0.
This is unrelated to the changes in this PR, but since we are doing the same
thing for the commit.Action field in the next commit, it makes sense to do it
for Status too for consistency. Modelling this as an enum feels more natural
than modelling it as a string, since there's a finite set of possible values.
And it saves a little bit of memory (not very much, since none of the strings
were heap-allocated, but still).
Instead, derive it from context at display time (if we're rebasing, it's the
first non-todo commit). This fixes the problem that unfolding the current
commit's files in the local commits panel would show junk in the frame's title.
Along the way we make sure to only display the "<--- YOU ARE HERE" string in the
local commits panel; previously it would show for the top commit of a branch or
tag if mid-rebase.
test: add an integration test for checkout branch by name
fix: fix full ref name of detached head
refactor: refactor current branch loader
chore: use field name explicitly
