No, you should not need to keep generated minimized versions under source control.
We have had problems when adding generated files into source control (TFS), because of the way TFS sets local files to be read-only. Tools that generate files as part of the build process then have write access problems (this is probably not a problem with other version control systems).
But importantly, all the:
- tools
- scripts
- source code
- resources
- third party libraries
and anything else you need to build, test and deploy your product should be under version control.
You should be able to check out a specific version from source control (by tag or revision number or the equivalent) and recreate the software exactly as it was at that point in time. Even on a 'fresh' machine.
The build should not be dependent on anything which is not under source control.
Scripts: build-scripts whether ant, make, MSBuild command files or whatever you are using, and any deployment scripts you may have need to be under version control - not just on the build machine.
Tools: this means the compilers, minimizers, test frameworks - everything you need for your build, test and deployment scripts to work - should be under source control. You need the exact version of those tools to be available to recreate to a point in time.
The book 'Continuous Delivery' taught me this lesson - I highly recommend it.
Although I believe this is a great idea - and stick to it as best as possible - there are some areas where I am not 100% sure. For example the operating system, the Java JDK, and the Continuous Integration tool (we are using Jenkins).
Do you practice Continuous Integration? It's a good way to test that you have all the above under control. If you have to do any manual installation on the Continuous Integration machine before it can build the software, something is probably wrong.