You can't determine the versions of the binary packages from looking at a source package, as the versions don't always map 1:1, so trying to reject at the source stage is a waste of time and effort.
Take, for example, php-imap, with a source version of 5.1.2-1, which generates binary packages php5-imap version 5.1.2-1 and php4-imap version 4:5.1.2-1 (note the epoch). There's no way to test for that, as it's done in debian/rules.
You can't determine the versions of the binary packages from looking at a source package, as the versions don't always map 1:1, so trying to reject at the source stage is a waste of time and effort.
Take, for example, php-imap, with a source version of 5.1.2-1, which generates binary packages php5-imap version 5.1.2-1 and php4-imap version 4:5.1.2-1 (note the epoch). There's no way to test for that, as it's done in debian/rules.