Hey ,
Ideally, you would use perforces merge/integrate functionality. It is recommended that you maintain a clean, unchanged version of ue4 on your server and you can create a branch from that.
This makes merge/integrate a lot easier in the future as perforce maintains history of both of the branches, the clean ue4 version and your dev branch.
When you have a version you want to upgrade to, in your workspace sync the Clean branch to latest. Then locally, not in perforce, Delete all the files from windows explorer.
Paste the clean updated version of ue4 into the folder on your machine. In P4V, right click on the qa branch and choose to “Reconcile offline work…”
This will build a changelist of all the changes which have occurred between ue4 versions.
Go ahead and submit that.
Next right click on the clean branch and merge/integrate. Choose your dev branch as the target.
This will build a changelist which hosts all the changes. You can then look at resolving any conflicts that may have occured, I.e. if you made changes to engine files between versions.
Make sure this all works by building your game and run it, if theres any issues, you can just revert that cl. If there isnt, submit. And your perforce dev server should be up to date.
Hope this helps.
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