first parent, commit graph layout, and pull merge direction

Hi everyone,

I'm just looking into better displays of the commit graph (as displayed with gitk, smartgit, fisheye) - they tend to quickly dissolve into a heap of spaghetti.

We had the idea that treating the first parent specially would have some advantage here - including graphically indicating which one of the parents of a commit is the first parent. (For instance, by letting that line leave the commit node at the top/bottom, and the other(s) to the side.)

A short trial showed that representing first parent chains as straight lines in the graph does actually improve understandability, as feature branches clearly stand out as separate lines even when they no longer carry a branch name.

Does any GUI already do that (treat first parent specially), or does anybody think of doing such? I don't quite dare to jump into the gitk code yet.

Also, there is an implication with 'git pull': You'd expect the master branch to be a first parent line, but when I do a small thing directly on master and need to pull before pushing back, then origin/master is merged into my branch, and thus my side branch becomes the first parent line.

So, feature discussion request: Invert the parent ordering when doing git pull from upstream? Configurably so?

We actually thought about putting a restriction into our blessed repo that it not only restricts to fast-forward pushed, but further to only allow pushing new things that have the old branch head in the first parent chain.

What do you think?