AFAIK the version number is the released version of upstream application foo and the release number is the built of RPM package foo. Say releasing upstream foo-0.1.4 creates foo-0.1.4-1.rpm. Patching upstream foo-0.1.4 then would be foo-0.1.4-2.rpm.
I thought that patching upstrem would change version number from e.g. foo-0.1.4 to foo-0.1.5 ?
What means patching upstream in this example ?