Understanding diff against current ?

[Borat Sagdiyev]

I have two branches in source tree - master and branch-1. The current branch is master (in bold text in source tree). I right click on branch-1 and do "diff against current". Does this mean "git diff master branch-1", OR "git diff branch-1 master" ?

I wanted to merge branch-1 into master. But, before merging I want to see the changes which branch-1 would introduce into master. Should I select master as current & then then diff against branch-1 or vice versa ?

As an aside, is there a way to see all the commands which source tree performs in the background ? Thanks.

[Mikael Sandberg]

The diff against current is the equivalent of git diff master...branch

[Borat Sagdiyev]

@Mikael Sandberg- In your answer, you have assumed that master is the current branch, right ?

[Mikael Sandberg]

Sorry, should have added that. My example assumes branch is the current branch.

[Borat Sagdiyev]

@Mikael Sandberg- Sorry your previous comment is not clear.
"My example assumes branch is the current branch." Which branch are you talking about after "assumes branch ???..."

[Mikael Sandberg]

The command git diff master...branch will show all changes made in branch that have not yet been merged into master, same as compare against current in Sourcetree assuming branch is your current branch.