fix(finish): Use the start point branch when finishing

[dermojo]

When finishing a branch, check the (stored) start point used to create the branch. If it differs from the configured start point, merge back to this branch instead. This ensures that e.g. creating releases from another branch works as expected.

Resolves #71
Refs #36

Remarks

• No tests added yet
• Docs not updated yet

Review focus:

• Current tests suggest to me that the changed behavior is NOT intended
• However, the current test (TestFinishUsesConfiguredParent) still passes and should be adapted
• I want to start a discussion for this changed behavior nevertheless because I need this fix

[bmcdonnell-fb]

#71 (comment)

[alexrinass]

Thanks for the PR and for the detailed discussion in #71 — this is a real workflow need and we want to support it properly.

That said, we'd like to think this through a bit more before merging. As discussed in #71, we want to explicitly differentiate between the starting point (where a branch is created from) and the parent (where it merges back into). Your fix uses the stored start point as the merge target, which works for your use case but may not be the right default for all scenarios (e.g., stacked feature branches where finish should target the configured parent, not the branch it was created from).

We're leaning toward introducing an explicit --parent override on start that gets stored and used by finish, rather than implicitly deriving the merge target from the start point. This makes the intent clearer and avoids surprising behavior for users who start from one branch but want to finish to another.

We'll keep this PR open as a reference while we work on the design. Appreciate the contribution and the patience!

[bmcdonnell-fb]

We're leaning toward introducing an explicit --parent override on start that gets stored and used by finish

I think a better name for the override parameter would be --target, or --merge-target? Since the existing [base] parameter is the "parent" (ancestor) of the commits the user will be creating in the release branch, in the Git sense.

[dermojo]

Thanks for the feedback, your time investment in this is appreciated!

I like the proposed solution :)
If I may add a suggestion: It would be handy to have a config switch to automatically use the start point as merge target (that would avoid specifying the base branch 2x during start).