In the pull request option. Upon selecting two branch, github notifies if the two branches has any conflict. What is the command to find branch conflict?
To compute the merge results of 2 revisions without making real changes:
git merge-tree $(git merge-base <rev1> <rev2>) <rev1> <rev2>
The 2 revisions have at least 1 common ancestor. If there're conflicts, the marks like <<<<<<<, =======, >>>>>>> will be printed.
Update: for binary file conflicts, the log includes lines like
warning: Cannot merge binary files: <binary path> (.our .vs .their)