Worktree HEAD traceability

[miquella]

Recently I was thinking about #928 and realized something that may be missing.

When running smartlog, by default it shows anything traceable from my current HEAD as well as any local branches, correct?

One of the core reasons to use worktrees is so that all of the commits from one worktree are immediately available in other worktrees from the same repo. So it strikes me that perhaps smartlog should also show anything traceable from any worktree's HEAD.

Each worktree's HEAD could be denoted similar to branches, that way when switching between worktrees, you don't lose track of recently committed work (I employ a lot of worktrees, so I feel this pain often 😆).

[arxanas]

This sounds reasonable, although there is currently no query to find all worktree HEADs. I would accept a PR implementing this. We would probably have to define a revset that expands to all worktree HEADs along the way.

In theory, with #1095, we would reflect new commits in any worktree across all worktrees, so you would be able to see all work in progress from any worktree (although this is a different thing from showing all worktree HEADs; for example, it wouldn't show branches that were pulled from a remote and not registered via the post-commit hook).