makepkg: don't try to verbump PKGBUILD on /dev/stdin
This works around an edge case where we try to change the $pkgver and
$pkgrel of a VCS PKGBUILD passed in standard input, which fails on
missing write permissions in /dev.
As an added bonus, we avoid a second (costly) full re-sourcing of the
PKGBUILD, and simply reassign the variables that may have changed to
ensure that in the non-write case we create the new package with the
Signed-off-by: Dave Reisner <email@example.com>
Extreme edge cases ftw.
Allan, correct me if I'm wrong that this is the only place where we actually
modify the PKGBUILD itself. I had myself a grep around and couldn't find
anything else -- I just want to make sure I'm not going to hit some crazy
pitfall by avoiding the second resourcing. I did do some simple testing and all
seems to be well, but you probably know this portion of the code better than I