I am not sure whether this is a Git or IntelliJ problem we are facing. Assuming the following using Git integration in IntelliJ:
User A changes a text file and commits and pushes this change to branch branch1
User B changes the same text file but in a different line and commits to branch1
User B fetches the remote repository and merges the remote branch1 into the local branch1
Current Behavior: It merges wihout any conflicts (since different lines?)
Wanted Behavior: Conflict Resolution Window popups up and User must decide whether to apply all none conflicting changes.
But why you might want this behvaior?: Sometimes we had troubles with markup or js files, where one developer changed something at the top (e.g. removed an unused function) and a another developer was relying on this. One must have very costly ui tests if you want to get informed about those breaks. Especially if it is just markup (e.g. jsf tags, params)