[PATCH 0/9] send-email: various optimizations to speed up by >2x

This is on top of my just-submitted [1] which in turn is on top of send-email work of mine sitting in "next".

I was meaning to hold off on these patches for a bit, but given the concurrent on-list discussion about doing config discovery in send-email I wanted to send this now.

This combines by not-picked-up[1] recent patches to remove the support for the "sendemail.smtpssl" variable with the later patches showing where that effort was really going.

As noted in the subject this speeds up git-send-email invocations by ~2x or more, and brings the very slow t9001 test from running in ~26s on my box to ~12s. It's no longer consistently the slowest test I run.

This is basically done in two ways: We lazily invoke "git config" to get config, before it's very eager, and deferring Perl compilation with s/use/require/g.

1. https://lore.kernel.org/git/patch-1.1-92571a8cf7-20210512T094803Z-avarab@gmail.com/
2. https://lore.kernel.org/git/cover-0.2-00000000000-20210411T144128Z-avarab@gmail.com/

Ævar Arnfjörð Bjarmason (9):
  send-email: remove non-working support for "sendemail.smtpssl"
  send-email: refactor sendemail.smtpencryption config parsing
  send-email: lazily load config for a big speedup
  send-email: lazily shell out to "git var"
  send-email: use function syntax instead of barewords
  send-email: get rid of indirect object syntax
  send-email: lazily load modules for a big speedup
  perl: lazily load some common Git.pm setup code
  send-email: move trivial config handling to Perl

 Documentation/config/sendemail.txt |   3 -
 git-send-email.perl                | 145 +++++++++++++++++------------
 perl/Git.pm                        |  49 +++++-----
 3 files changed, 111 insertions(+), 86 deletions(-)