I've noticed that rebasing from master when there are no conflicts does not cause existing reviews to be dismissed.

In the docs, github describes the "Dismiss stale pull requests ..." setting as "New reviewable commits pushed to a matching branch will dismiss pull request review approvals".

What does "reviewable commit" mean here?

CodePudding user response：

If you push any change to the branch manually, or you create any change in the web interface (e.g., applying a suggested change) other than a merge from the destination branch (or a rebase onto it, as appropriate), then GitHub will dismiss the review.

Basically, updating with the main branch using the GitHub tools for that does not cause a reviewable commit and everything else does. Note that in general it is nearly impossible to determine whether a manual merge or rebase introduces any "meaningful" change and therefore doing it manually always dismisses approvals.