How to check the conflict of two branch, but not need to merge them?

Question

I can't merge two branch because of release step of our project, but I want to know whether there are conflict of two branch. How can I do this?

Answer 1

Suppose you are on the master branch and you would like to test if the dev branch can be merged without conflict into the master.

# In the master branch git merge dev --no-ff --no-commit 

After that, you will be able to know if there's a conflict or not.

To return in a normal situation, just abort the merge:

git merge --abort

According to the git documentation:

--ff
Do not generate a merge commit if the merge resolved as a fast-forward, only update the branch pointer. This is the default behavior.

-no-ff
Generate a merge commit even if the merge resolved as a fast-forward.

--commit
Perform the merge and commit the result. This option can be used to override --no-commit.

--no-commit
With --no-commit perform the merge but pretend the merge failed and do not autocommit, to give the user a chance to inspect and further tweak the merge result before committing.