Robert Elz wrote:
test for what you need to know - exactly - never simply assume that if X is detected, then (an unrelated) Y will also exist
This is good advice. It's a primary design philosophy of Autoconf: test for what you need, not for version numbers. Although you can't always do it, it's better to do it when you can.
saving a few bytes of download time in an environment when half the world are streaming movies (or porn) and the rest are trying to download kde or openoffice just isn't an objective that matters.
Admittedly it's not a big deal, but if we're upgrading tzdata in 5 billion mobile devices ten times per year and saving 50 kB per upgrade, that's 250 TB of mobile data and Internet traffic saved worldwide per year. Although this is only a tiny fraction of total use (Cisco predicts 200 EB for such traffic in 2018), even a 1 part-per-million decrease would be a (tiny) win. It'd be like Hogan's Heroes vs the German army; you get only small victories, but you do what you can and every bit helps. My source for traffic estimates is the last page of: https://www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-n...