I only use a few packages from the Courier MTA, but the spec file always installed some files for MySQL, PostgreSQL and Fax support.
This is because the configuration files are installed via sysconftool from %post, only.
I haven't looked at your changes in detail, but I suspect that fresh install on a pristine systems will be broken by your patch, because after installing one of those subpackages sysconftool will not run to actually install the configuration files. You could've easily missed that if you were working on a system with an existing Courier install, where the configuration files are already there.
The fact that some configuration files are installed by the main package, instead of a more appropriate subpackage, is not the end of the world.
Also, the patch cleans up how filelist1 is finally processed to produce filelist for the main package. Before this patch, each package would grab the files from filelist1 and place the lines into their own filelist and then the reverse was done to filelist1 to produce filelist.
The patch changes it to use sort and uniq to automatically produce filelist from filelist1 and the per package filelist.* files by using only the unique lines from filelist1.
Your implementation looks wrong. Looks you're putting EVERYTHING into filelist, instead of just the main package's files.
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