On Wed, Jul 31, 2013 at 10:13:20PM +0200, Thomas Rast wrote: > When using pathspec filtering in combination with diff-based log > output, parent simplification happens before the diff is computed. > The diff is therefore against the *simplified* parents. > > This works okay, arguably by accident, in the normal case: > simplification reduces to one parent as long as the commit is TREESAME > to it. So the simplified parent of any given commit must have the > same tree contents on the filtered paths as its true (unfiltered) > parent. > > However, --full-diff breaks this guarantee, and indeed gives pretty > spectacular results when comparing the output of > > git log --graph --stat ... > git log --graph --full-diff --stat ... > > (--graph internally kicks in parent simplification, much like > --parents).
Your description (and solution) make a lot of sense to me. Another code path that has a similar problem is the "-g" reflog walker. It rewrites the parents based on the reflog, and the diffs it produces are mostly useless (e.g., try "git stash list -p"). Should we be applying the same technique there? I guess it might bother people who really want to see the diff between two lines in the reflog (e.g., comparing the results stored by "rebase" with the previous version). I think that is rare enough that "git diff" would be a better tool in that case, though. And arguably, "log -g" should not be rewriting the parents at all, because it makes "--graph" pointless (and indeed, we disallow the combination). So potentially the solution is to stop the rewriting entirely, not mask it for the diffs. But doing so might be a good interim solution until somebody feels like rewriting the reflog walker. -Peff -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
