Merge branch 'tr/log-full-diff-keep-true-parents' into maint

Output from "git log --full-diff -- <pathspec>" looked strange, because comparison was done with the previous ancestor that touched the specified <pathspec>, causing the patches for paths outside the pathspec to show more than the single commit has changed. * tr/log-full-diff-keep-true-parents: log: use true parents for diff when walking reflogs log: use true parents for diff even when rewriting