Compare the output of TW vs Leap:

### TUmbleweed ###
> rpm -q --provides MozillaFirefox
MozillaFirefox = 41.0-1.3
MozillaFirefox(x86-64) = 41.0-1.3
appdata()
appdata(firefox.appdata.xml)
application()
application(firefox.desktop)
browser(npapi)
firefox = 41.0
firefox = 41.0-1.3
mimehandler(application/vnd.mozilla.xul+xml)
mimehandler(application/x-xpinstall)
mimehandler(application/xhtml+xml)
mimehandler(text/html)
mimehandler(text/mml)
mimehandler(text/xml)
mimehandler(x-scheme-handler/ftp)
mimehandler(x-scheme-handler/http)
mimehandler(x-scheme-handler/https)
mozilla-kde4-version = 6
web_browser

### Leap 42.1 ###
> rpm -q --provides MozillaFirefox
MozillaFirefox = 41.0-1.3
MozillaFirefox(x86-64) = 41.0-1.3
browser(npapi)
firefox = 41.0
firefox = 41.0-1.3
mozilla-kde4-version = 6
web_browser

Specifically, all things that are detected by rpm external provides handlers
are not added (this for example results in an error in zypper verify, whenever
FF is installed, as MozillaFirefox does not provide
appdata(firefox.appdata.xml)

As per the .spec file, that seems to be somewhat intentional
%define _use_internal_dependency_generator 0

As a minimal work around, appdata(firefox.appdata.xml) should be provided at
least in the rpm meta data (I have no idea why on TW this is provided and on
Leap not... the .spec files are identical. which means the override should also
work on TW.. but maybe rpm 4.12 no longer honors that; adding mlschroe to CC
for that case)