FR: blame view for a diff

[vt-alt]

Sometimes (for example when porting) it's useful to see a blame view for a diff output. It could be cool if tig supports this mode.

Also, this could be useful in commit view -- if user will be able to toggle viewing commit diff and blamed commit diff.

[adlai]

I was first going to respond that this request is illogical, because git-blame only works on individual commits; however, after further consideration of what you might have intended, I think you're referring to diffs between ranges of commits, where the blame output is nontrivial... however, it is probably better implemented first as an extension to git-blame rather than glued onto tig.