Description of problem:
Debugging a yum depsolving problem I noticed I wasn't getting results back when I checked to see if an installed package obsoleted a package that was being proposed to be installed.

I started testing various tests and found that nothing is ever returned as matching obsoletes by name or complete. 



Example code:
import rpm
ts = rpm.TransactionSet()
mi = ts.dbMatch(1090, 'mod_gzip')
for hdr in mi:
    print hdr['name']

on the system I have it  should return 'httpd', at the least.

I also tested it using rpm.RPMTAG_OBSOLETES, rpm.RPMTAG_OBSOLETENAME  to no avail.

Finally, I noticed some odd output in rpm -qa --obsoletes for example:
(none)(none)(none)baobab

in any case - I'm pretty sure ts.dbMatch() used to work against obsoletes, but it doesn't seem to work anymore.