I have searched the P4 documentation and knowledge bases and I cannot find if there are any keyboard shortcuts to perform common actions when diffing files.
I know about the next and previous change (CTRL+1 and CTRL+2 respectively) however there are more common actions.
So, are there any undocumented keyboard shortcuts that you know?
For example:
Nothing that I know of, but the 2012.1 release of P4V does support configurable keyboard shortcuts. I'm not sure if that's extending into P4Merge, but it'd be worth asking for the feature.