the assumption is that if somebody bothers to actually specify a file name, they'll most probably go all the way to specify the *correct* file name. otherwise, they'll use -L/-l flags to specify the libs in a cross-platform way and rely on qmake's magic. this code was initially added for the purpose of invoking findHighestVersion() under windows. this has been off by default for a while now. at some point, the code did also swap qt for qt-mt and vice versa if the specified one was missing. this is obviously gone for a while as well. the unix code was pretty much broken since day one: there was a regex match on lib<stub>.* against <stub> itself, which obviously could not have ever succeeded. consequently, the subsequent code ran into a path that tried the file name with a trailing dot (instead of a new extension), which never produced anything meaningful. [ChangeLog][qmake][Important Behavior Changes] The library lookup has been simplified. It may be necessary to be more explicit in some edge cases now. Change-Id: I5804943f1f7a16d38932b31675caabbda33eada7 Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>