"git $builtin -h" bypasses the usual repository setup and calls the
cmd_$builtin() function, expecting it to show the help text.

Unfortunately the commands in the log- and the diff- family want to
call into the revisions machinery, which by definition needs to have
a repository already discovered, before they can parse the options.

Handle the "git $builtin -h" special case very early in these
commands to work around potential issues.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Signed-off-by: Junio C Hamano <gitster@pobox.com>

When "git checkout", "git merge", etc. manipulates the in-core
index, various pieces of information in the index extensions are
discarded from the original state, as it is usually not the case
that they are kept up-to-date and in-sync with the operation on the
main index.  The untracked cache extension is copied across these
operations now, which would speed up "git status" (as long as the
cache is properly invalidated).

* dt/unpack-save-untracked-cache-extension:
  unpack-trees: preserve index extensions

A follow-up hotfix for a topic already in 'master'.

* js/larger-timestamps:
  name-rev: change a "long" variable to timestamp_t

"git send-email" now uses Net::SMTP::SSL, which is obsolete, only
when needed.  Recent versions of Net::SMTP can do TLS natively.

* dk/send-email-avoid-net-smtp-ssl-when-able:
  send-email: Net::SMTP::SSL is obsolete, use only when necessary

A recent update to t5545-push-options.sh started skipping all the
tests in the script when a web server testing is disabled or
unavailable, not just the ones that require a web server.  Non HTTP
tests have been salvaged to always run in this script.

* jc/skip-test-in-the-middle:
  t5545: enhance test coverage when no http server is installed
  test: allow skipping the remainder

The recently introduced "[includeIf "gitdir:$dir"] path=..."
mechansim has further been taught to take symlinks into account.
The directory "$dir" specified in "gitdir:$dir" may be a symlink to
a real location, not something that $(getcwd) may return.  In such
a case, a realpath of "$dir" is compared with the real path of the
current repository to determine if the contents from the named path
should be included.

* ab/conditional-config-with-symlinks:
  config: match both symlink & realpath versions in IncludeIf.gitdir:*

There is no good reason why "git fetch $there $sha1" should fail
when the $sha1 names an object at the tip of an advertised ref,
even when the other side hasn't enabled allowTipSHA1InWant.

* jt/fetch-allow-tip-sha1-implicitly:
  fetch-pack: always allow fetching of literal SHA1s

"git send-email" learned to run sendemail-validate hook to inspect
and reject a message before sending it out.

* jt/send-email-validate-hook:
  send-email: support validate hook

perf-test update.

* jh/memihash-opt:
  p0004: don't error out if test repo is too small
  p0004: don't abort if multi-threaded is too slow
  p0004: use test_perf
  p0004: avoid using pipes
  p0004: simplify calls of test-lazy-init-name-hash