tests: Introduce test_seq

Jeff King wrote:

	The seq command is GNU-ism, and is missing at least in older BSD
	releases and their derivatives, not to mention antique
	commercial Unixes.

	We already purged it in b3431bc (Don't use seq in tests, not
	everyone has it, 2007-05-02), but a few new instances have crept
	in. They went unnoticed because they are in scripts that are not
	run by default.

Replace them with test_seq that is implemented with a Perl snippet
(proposed by Jeff).  This is better than inlining this snippet
everywhere it's needed because it's easier to read and it's easier
to change the implementation (e.g. to C) if we ever decide to remove
Perl from the test suite.

Note that test_seq is not a complete replacement for seq(1).  It
just has what we need now, in addition that it makes it possible for
us to do something like "test_seq a m" if we wanted to in the
future.

There are also many places that do `for i in 1 2 3 ...` but I'm not sure
if it's worth converting them to test_seq.  That would introduce running
more processes of Perl.

Signed-off-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation: do not mention .git/refs/* directories

It is an implementation detail that a new tag is created by adding a
file in the .git/refs/tags directory.  The only thing the user needs
to know is that a "git tag" creates a ref in the refs/tags namespace,
and without "-f", it does not overwrite an existing tag.

Inspired by a report from 乙酸鋰 <ch3cooli@gmail.com>; I think I
caught all the existing mention in Documentation/ directory in the
tip of 1.7.9.X maintenance track, but we may have added new ones
since then.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/CodingGuidelines: spell out more shell guidelines

In earlier days, "imitate the style in the neibouring code" was
sufficient to keep the coherent style, but over time some parts of
the codebase have drifted enough to make it ineffective.

Spell some of the guidelines out.

Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
rev-list docs: clarify --topo-order description

It was unclear what "--topo-order" was really about in the
documentation.  It is not just about "children before parent", but
also about "don't mix lineages".

Reword the description for both "--date-order" and "--topo-order",
and add an illustration to it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
gitcli: describe abbreviation of long options

Signed-off-by: Junio C Hamano <gitster@pobox.com>
man: git pull -r is a short for --rebase

Letting the "--rebase" option squat on the short-and-sweet single
letter option "-r" was an unintended accident and was not even
documented, but the short option seems to be already used in the
wild. Let's document it so that other options that begin with "r"
would not be tempted to steal it.

Signed-off-by: Miklos Vajna <vmiklos@suse.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Improved documentation for the ciabot scripts.

Signed-off-by: Eric S. Raymond <esr@thyrsus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the ciabot scripts completely self-configuring in the normal case.

Signed-off-by: Eric S. Raymond <esr@thyrsus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jk/maint-commit-check-committer-early' into maint-1.7.11

* jk/maint-commit-check-committer-early:
  commit: check committer identity more strictly
Merge branch 'bw/maint-1.7.9-solaris-getpass' into maint-1.7.11

* bw/maint-1.7.9-solaris-getpass:
  Enable HAVE_DEV_TTY for Solaris
  terminal: seek when switching between reading and writing
Merge branch 'lp/no-cmd-http-fetch' into maint-1.7.11

* lp/no-cmd-http-fetch:
  builtin.h: remove unused cmd_<foo> declarations
Merge branch 'mk/test-seq' into maint-1.7.11

Add a compatibility/utility function to the test framework.

* mk/test-seq:
  tests: Introduce test_seq
Merge branch 'jc/tag-doc' into maint-1.7.11

Our documentation used to assume having files in .git/refs/*
directories was the only to have branches and tags, but that is not
true for quite some time.

* jc/tag-doc:
  Documentation: do not mention .git/refs/* directories
Merge branch 'hv/coding-guidelines' into maint-1.7.11

In earlier days, "imitate the style in the neibouring code" was
sufficient to keep the coherent style, but over time some parts of
the codebase have drifted enough to make it ineffective.

* hv/coding-guidelines:
  Documentation/CodingGuidelines: spell out more shell guidelines
Merge branch 'jc/maint-rev-list-topo-doc' into maint-1.7.11

It was unclear what "--topo-order" was really about in the
documentation. It is not just about "children before parent", but
also about "don't mix lineages".

* jc/maint-rev-list-topo-doc:
  rev-list docs: clarify --topo-order description
Merge branch 'jc/maint-abbrev-option-cli' into maint-1.7.11

We did not document that many commands take unique prefix
abbreviations of long options (e.g. "--option" may be the only flag
that the command accepts that begin with "--opt", in which case you
can give "--opt") anywhere easy to find for new people.

* jc/maint-abbrev-option-cli:
  gitcli: describe abbreviation of long options
Merge branch 'mv/pull-r-for-rebase' into maint-1.7.11

A minor documentation update.

* mv/pull-r-for-rebase:
  man: git pull -r is a short for --rebase
Prepare for 1.7.11.6

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'maint-1.7.11' into maint

* maint-1.7.11:
  Prepare for 1.7.11.6
  Make the ciabot scripts completely self-configuring in the normal case.
  Improved documentation for the ciabot scripts.
  man: git pull -r is a short for --rebase
  gitcli: describe abbreviation of long options
  rev-list docs: clarify --topo-order description
  Documentation/CodingGuidelines: spell out more shell guidelines
  Documentation: do not mention .git/refs/* directories
  tests: Introduce test_seq