[Feature Request] merge-base comparison for working tree against specific ref #589
Description
Problem
Currently, when comparing a single revision against the working tree (e.g., :DiffviewOpen origin/main), it shows all differences between that revision and the current working tree. However, I want to see only the changes they've made since their branch diverged from the target branch. While the triple-dot syntax (origin/main...HEAD) provides this functionality for committed changes, it doesn't include uncommitted changes in the working tree.
Proposed Solution
Add a --merge-base flag that modifies the behavior when comparing a single revision with the working tree:
:DiffviewOpen --merge-base origin/mainUse Cases
- Pre-PR review: See all changes (committed and uncommitted) that will be included in a pull request
- Feature branch development: Understand the full scope of changes on a feature branch relative to its base
- Clean diffs: Avoid seeing unrelated changes that exist in the target branch but not in the merge-base