Maybe in it is sufficient to set $r->subprocess_env(HTTPS=>'on') in a
PostReadRequest handler. Maybe even PerlSetEnv outside any <Location> or
<Directory> might help. This will also set environment variables very early.
$ENV{HTTPS} is not good.
Ah, I'd neglected to mention that I was using subprocess_env as well in the same spot. I just tried PerlSetEnv in the VirtualHost on the backend server handling port 443 (as well as regular SetEnv for good measure) but same story.
It's definitely getting set too, since I tacked the HTTPS env var onto the redirected URL in mod_rewrite and ?on dutifully shows up.
So before the transhandling phase, is there any way to take the URL, futz with it via Apache::URI, and then reinject that as the URL the subsequent phases will see (assuming it's not just updating the URL in modperl alone and that C-based modules can see the change as well, e.g. mod_rewrite)?
