sane_execvp(): ignore non-directory on $PATH

When you have a non-directory on your PATH, a funny thing happens:

	$ PATH=$PATH:/bin/sh git foo
	fatal: cannot exec 'git-foo': Not a directory?

Worse yet, as real commands always take precedence over aliases,
this behaviour interacts rather badly with them:

	$ PATH=$PATH:/bin/sh git -c alias.foo=show git foo -s
	fatal: cannot exec 'git-foo': Not a directory?

This is because an ENOTDIR error from the underlying execvp(2) is
reported back to the caller of our sane_execvp() wrapper as-is.

Translating it to ENOENT, just like the case where we _might_ have
the command in an unreadable directory, fixes it.  Without an alias,
we would get

	git: 'foo' is not a git command. See 'git --help'.

and we use the 'foo' alias when it is available, of course.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
macos: lazily initialize iconv

In practice, the majority of paths do not have utf8 that needs
the canonicalization. Lazily call iconv_open()/iconv_close() to
avoid unnecessary overhead.

Credits to Ralf Thielow and Linus Torvalds for reviews and
comments.  Bugs are still mine.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
send-email: improve RFC2047 quote parsing

The RFC2047 unquoting, used to parse email addresses in From and Cc
headers, is broken in several ways:

* It erroneously substitutes ' ' for '_' in *the whole* header, even
  outside the quoted field. [Noticed by Christoph.]

* It is too liberal in its matching, and happily matches the start
  of one quoted chunk against the end of another, or even just
  something that looks like such an end. [Noticed by Junio.]

* It fundamentally cannot cope with encodings that are not a
  superset of ASCII, nor several (incompatible) encodings in the
  same header.

This patch fixes the first two by doing a more careful decoding of
the outer quoting (e.g. "=AB" to represent an octet whose value is
0xAB).  Fixing the fundamental issues is left for a future, more
intrusive, patch.

Noticed-by: Christoph Miebach <christoph.miebach@web.de>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
setup: clarify error messages for file/revisions ambiguity

The previous "Use '--' to separate filenames from revisions" may sound
obvious for an old-time Unix user, but does not make it clear how to use
this '--'. In addition to mentionning this '--', give an idea of what the
new command should look like.

Ideally, we could provide cut-and-paste ready commands based on the
command that just failed, but we have no easy access to argv[] in this
place of the code.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
grep: add a grep.patternType configuration setting

The grep.extendedRegexp configuration setting enables the -E flag on grep
by default but there are no equivalents for the -G, -F and -P flags.

Rather than adding an additional setting for grep.fooRegexp for current
and future pattern matching options, add a grep.patternType setting that
can accept appropriate values for modifying the default grep pattern
matching behavior. The current values are "basic", "extended", "fixed",
"perl" and "default" for setting -G, -E, -F, -P and the default behavior
respectively.

When grep.patternType is set to a value other than "default", the
grep.extendedRegexp setting is ignored. The value of "default" restores
the current default behavior, including the grep.extendedRegexp
behavior.

Signed-off-by: J Smith <dark.panda@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff_setup_done(): return void

diff_setup_done() has historically returned an error code, but lost
the last nonzero return in 943d5b7 (allow diff.renamelimit to be set
regardless of -M/-C, 2006-08-09).  The callers were in a pretty
confused state: some actually checked for the return code, and some
did not.

Let it return void, and patch all callers to take this into account.
This conveniently also gets rid of a handful of different(!) error
messages that could never be triggered anyway.

Note that the function can still die().

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge-recursive: eliminate flush_buffer() in favor of write_in_full()

flush_buffer() is a thin wrapper around write_in_full() with two very
confusing properties:

* It runs a loop to handle short reads, ensuring that we write
  everything.  But that is precisely what write_in_full() does!

* It checks for a return value of 0 from write_in_full(), which cannot
  happen: it returns this value only if count=0, but flush_buffer()
  will never call write_in_full() in this case.

Remove it.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
include agent identifier in capability string

Instead of having the client advertise a particular version
number in the git protocol, we have managed extensions and
backwards compatibility by having clients and servers
advertise capabilities that they support. This is far more
robust than having each side consult a table of
known versions, and provides sufficient information for the
protocol interaction to complete.

However, it does not allow servers to keep statistics on
which client versions are being used. This information is
not necessary to complete the network request (the
capabilities provide enough information for that), but it
may be helpful to conduct a general survey of client
versions in use.

We already send the client version in the user-agent header
for http requests; adding it here allows us to gather
similar statistics for non-http requests.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cherry-pick: add --allow-empty-message option

Scripts such as "git rebase -i" cannot currently cherry-pick commits
which have an empty commit message, as git cherry-pick calls git
commit without the --allow-empty-message option.

Add an --allow-empty-message option to git cherry-pick which is passed
through to git commit, so this behaviour can be overridden.

Signed-off-by: Chris Webb <chris@arachsys.com>
Reviewed-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jc/maint-sane-execvp-notdir' into jch

"git foo" errored out with "Not a directory" when the user had a non
directory on $PATH, and worse yet it masked an alias "foo" to run.

Not urgent (non regression).

* jc/maint-sane-execvp-notdir:
  sane_execvp(): ignore non-directory on $PATH
Merge branch 'jc/sanitize-nkd-lazy-iconv-open' into jch

Teach the code that works around NKD/NKC gotcha on MacOS to call
iconv_open() only when it is necessary, in the hope of avoiding
set-up overhead.

Not urgent (non regression).

* jc/sanitize-nkd-lazy-iconv-open:
  macos: lazily initialize iconv
Merge branch 'tr/maint-send-email-2047' into jch

"git send-email" did not unquote encoded words that appear on the
header correctly, and lost "_" from strings.

Not urgent (non regression).

* tr/maint-send-email-2047:
  send-email: improve RFC2047 quote parsing
Merge branch 'cw/cherry-pick-allow-empty-message' into jch

"git cherry-pick" by default stops when it sees a commit without any
log message.  The "--allow-empty-message" option can be used to
silently proceed.

Not urgent (non regression).

* cw/cherry-pick-allow-empty-message:
  cherry-pick: add --allow-empty-message option
Merge branch 'jk/version-string' into jch

Leftover bits from the "git version" code restructuring, that
actually give us an ability to expose the Git version over the wire
in the protocol exchange.

* jk/version-string:
  include agent identifier in capability string
Merge branch 'mm/die-with-dashdash-help' into jch

Reword error messages.

* mm/die-with-dashdash-help:
  setup: clarify error messages for file/revisions ambiguity
Merge branch 'tr/merge-recursive-flush' into jch

Remove unnecessary code.

* tr/merge-recursive-flush:
  merge-recursive: eliminate flush_buffer() in favor of write_in_full()

Conflicts:
	merge-recursive.c
Merge branch 'tr/void-diff-setup-done' into jch

Remove unnecessary code.

* tr/void-diff-setup-done:
  diff_setup_done(): return void

Conflicts:
	merge-recursive.c
Merge branch 'js/grep-patterntype-config' into jch

"grep" learned to use a non-standard pattern type by default if a
configuration variable tells it to.

* js/grep-patterntype-config:
  grep: add a grep.patternType configuration setting