I think it's time to actualy fix this thing. I propose a new $^H (or %^H) hint that selects if ARGV magic open uses two-arg or three-arg open. What would matter is the value in effect at the moment of the open. I propose a pragmata to select it, and an additional "lock" feature, which would not allow changing the value after that point (in execution order, allowing it to be a feature of the module code, not the core).
IOW: use magic::ARGV qw(safe lock); allows you to trust all code from that point on. (use magic::ARGV qw(safe); wouldn't lock it in, so it could be explicitly overruled, use magic::ARGV qw(more-magic); would give back the old behaviour. All that's left is to get better names, perhaps change the default from more-magic to safe, and actualy code the thing.
Agree, disagree? Think I should be saying this on p5p already?
Warning: Unless otherwise stated, code is untested. Do not use without understanding. Code is posted in the hopes it is useful, but without warranty. All copyrights are relinquished into the public domain unless otherwise stated. I am not an angel. I am capable of error, and err on a fairly regular basis. If I made a mistake, please let me know (such as by replying to this node).