[ptsneves]

Yes, except git log will show all the commits that got into the branch, while with merge you need git log -m otherwise there are invisible commits(and diffs) in a pretty common workflow. I don’t know why this is the default behaviour.

Git log only shows one tree not parallel trees from the merge.

[paulddraper]

? Not sure what you mean.

git log will show all ancestors.

And git diff shows any difference between two refs.

Nothing invisible unless you deliberately make it so.

[PhilipRoman]

Git log (and many other tools as well) pretend that merge commits do not introduce changes. I learned about it in the hard way when someone managed to implement an entirely new feature, contained within a hidden merge commit.

It's only partially the fault of Git - the entire idea of a merge requires new concepts like 3-way diff, which are not needed for rebased commits. I'm not even sure that most software like GitHub can display such a diff.

[tsimionescu]

The blog post explains it pretty clearly: git log -p doesn't show the diff for those merge commits like it does for a normal commit.