Deploying big release branches, steps to take (dry run merge and checkup)

If you have big sprint with big amount of task and put all of that into feature branch that you need to deploy (merge to master) then it is good to have one big final checkup before doing that. So what I do is this, go to your master branch and either make one temp branch from it like "master_temp" or do it directly there. For extra caution I use temp branch. So when on this temp master branch you want to merge your release branch, but you want to do kind of dry run (especially if doing on real master) you can do it with this line 

git merge --no-commit --no-ff <branch-name>

with that, you can get all the changes you will make once you merge this branches for real. Write 

git status

and see all the files that changed/are added/are deleted. Make a list of the ones you think you need to double check and then go to those files, check each of them and what changed with

git diff --cached filepath/filename

when you find which one are problematic, or maybe changed by mistake and should be reset to value in master. Go to your release branch and reset each file you want to master value.

git checkout origin/master filename

or do some other changes if you need. After all that, you will have a cleaner release branch.
If you did this dry run on real master, run this command to clean up this dry run, it will be as nothing happened :)

git merge --abort