when using `rpm --percent`, the "%% xx\n" lines are not flushed. This makes the feature almost useless for parsing from non-tty programs, as progress is read in jerks making eg. progress bars based on this feature real ugly and a bad userexperience.
Created attachment 7829 [details] patch against rpm-4.0.2-0.27.src.rpm
Patch added in CVS, will be in rpm-4.0.2 final. Thanks for noticing.