Code simplification.

* rs/pop-commit:
  use pop_commit() for consuming the first entry of a struct commit_list

Instead of open-coding the function pop_commit() just call it.  This
makes the intent clearer and reduces code size.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

When we already know the length of a string (e.g., because
we just malloc'd to fit it), it's nicer to use memcpy than
strcpy, as it makes it more obvious that we are not going to
overflow the buffer (because the size we pass matches the
size in the allocation).

This also eliminates calls to strcpy, which make auditing
the code base harder.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

"git init empty && git -C empty log" said "bad default revision 'HEAD'",
which was found to be a bit confusing to new users.

* jk/log-missing-default-HEAD:
  log: diagnose empty HEAD more clearly

"git init empty && git -C empty log" said "bad default revision 'HEAD'",
which was found to be a bit confusing to new users.

* jk/log-missing-default-HEAD:
  log: diagnose empty HEAD more clearly

If you init or clone an empty repository, the initial
message from running "git log" is not very friendly:

  $ git init
  Initialized empty Git repository in /home/peff/foo/.git/
  $ git log
  fatal: bad default revision 'HEAD'

Let's detect this situation and write a more friendly
message:

  $ git log
  fatal: your current branch 'master' does not have any commits yet

We also detect the case that 'HEAD' points to a broken ref;
this should be even less common, but is easy to see. Note
that we do not diagnose all possible cases. We rely on
resolve_ref, which means we do not get information about
complex cases. E.g., "--default master" would use dwim_ref
to find "refs/heads/master", but we notice only that
"master" does not exist. Similarly, a complex sha1
expression like "--default HEAD^2" will not resolve as a
ref.

But that's OK. We fall back to a generic error message in
those cases, and they are unlikely to be used anyway.
Catching an empty or broken "HEAD" improves the common case,
and the other cases are not regressed.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Code and documentation clean-up to "git bisect".

* ad/bisect-cleanup:
  bisect: don't mix option parsing and non-trivial code
  bisect: simplify the addition of new bisect terms
  bisect: replace hardcoded "bad|good" by variables
  Documentation/bisect: revise overall content
  Documentation/bisect: move getting help section to the end
  bisect: correction of typo

We create a file BISECT_TERMS in the repository .git to be read during a
bisection. There's no user-interface yet, but "git bisect" works if terms
other than old/new or bad/good are set in .git/BISECT_TERMS. The
fonctions to be changed if we add new terms are quite few.

In git-bisect.sh:
	check_and_set_terms
	bisect_voc

Co-authored-by: Louis Stuber <stuberl@ensimag.grenoble-inp.fr>
Tweaked-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Antoine Delaite <antoine.delaite@ensimag.grenoble-inp.fr>
Signed-off-by: Louis Stuber <stuberl@ensimag.grenoble-inp.fr>
Signed-off-by: Valentin Duperray <Valentin.Duperray@ensimag.imag.fr>
Signed-off-by: Franck Jonas <Franck.Jonas@ensimag.imag.fr>
Signed-off-by: Lucien Kong <Lucien.Kong@ensimag.imag.fr>
Signed-off-by: Thomas Nguy <Thomas.Nguy@ensimag.imag.fr>
Signed-off-by: Huynh Khoi Nguyen Nguyen <Huynh-Khoi-Nguyen.Nguyen@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Teach "git log" and friends a new "--date=format:..." option to
format timestamps using system's strftime(3).

* jk/date-mode-format:
  strbuf: make strbuf_addftime more robust
  introduce "format" date-mode
  convert "enum date_mode" into a struct
  show-branch: use DATE_RELATIVE instead of magic number

Code clean-up.

* jk/still-interesting:
  revision.c: remove unneeded check for NULL