How to build a patch installer with rpm?
 

My use case is:

I build a package "mypack-1.0" which contains file a, b, and c.
I installed "mypack-1.0".
Then after a while, I think I've got a new version of file a.
So I tried to build a patch package "mypack-1.0-hotfix1", which only contain file a.

Then I want to install "mypack-1.0-hotfix1" on top of "mypack-1.0".

There will be patch package "mypack-1.0-hotfix2" for ever newer a.
patch package "mypack-1.0-sp1" for a and b.

I hope after installed "mypack-1.0", "mypack-1.0-hotfix1", "mypack-1.0-hotfix2". "mypack-1.0-sp1". I can uninstall them one by one without breaking anything.

This is a typical "patching".

Can anyone tell me how rpm can do it?

With rpm you would want to use -U or --upgrade. The hotfix1 and hotfix2 package would need to contain all the files a, b and c due to the fact that --upgrade will erase old package and install new version.

Also to revert back to original package use rpm --oldpackage.

-U is not what I want
 

I knew -U can do that. But this behavior is not good for me.

1) each patch has to contain all the binaries.
2) it will remove the whole old package. There might be customization in the old package.

I'm looking for patch tick other than -U.