Dale Rowley <ddrowley3@xxxxxxxx> writes: > Our branch history looked something like the following: > > B---C > / \ > A---D---E---H > \ / > F---G > > In commit D a few lines were added to a file, and then in commit G the same > lines were removed. When branches E and G were merged, those lines unexpectedly > re-appeared in the merge commit (H), even though no other commits had touched > that file. > > I think I understand why this happened: git-merge-base reports that the > common ancestor for E and G is A. Do you? I don't. D is the merge base between E and G. A and D are both common ancestor between E and G, but because D is a descendant of A, A is not a merge base (the definition of merge-base is "common ancestors none of whose children is common ancestor"). A is not. Are you sure you really have ancestry relationship between D and G? If the history were like this: B---C / \ A---D---E---H \ / F-------G and both D and F add the same set of "few lines", and G removes it, then I can understand how you would get these "removed by G" lines appear in H, as the side branch F--G didn't have no net effect on these lines and D is the only one that added them. It can happen if F is a cherry-pick of D and G is a revert of F, for example. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html