Is there a quick way to "git diff" from the point or branch origin?

Question

I have looked at various SO answers on using git diff and git revisions (HEAD, ORIG_HEAD, FETCH_HEAD, etc.) and I still haven't found an easy way to list the changes have been made since the beginning of the local branch, or since last rebase.

By easy I mean without having to look up and paste commit SHA or having to count how many commits I want to look back.

git diff origin/master is close, but it refers to remote which may have diverged since I checked out new branch from it.

I would expect something like git diff BASE_HEAD to be available.

...unless there's already a way to do that. Does anyone have the answer?

Answer 1

You can find the branch point using git merge-base. Consider master the mainline and dev the branch whose history you are interested in. To find the point at which dev was branched from master, run:

git merge-base --fork-point master dev 

We can now diff dev against this basis:

git diff $(git merge-base --fork-point master dev)..dev 

If dev is the current branch this simplifies to:

git diff $(git merge-base --fork-point master) 

For more information see the git-merge-base documentation.

Answer 2

Use git diff @{u}...HEAD, with three dots.

With two dots, or with HEAD omitted, it will show diffs from changes on both sides.

With three dots, it will only show diffs from changes on your side.

Edit: for people with slightly different needs, you might be interested in git merge-base (note that it has plenty more options than the other answer uses).