builtin: add git-check-mailmap command

Introduce command check-mailmap, similar to check-attr and check-ignore,
which allows direct testing of .mailmap configuration.

As plumbing accessible to scripts and other porcelain, check-mailmap
publishes the stable, well-tested .mailmap functionality employed by
built-in Git commands.  Consequently, script authors need not
re-implement .mailmap functionality manually, thus avoiding potential
quirks and behavioral differences.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4203: test check-mailmap command invocation

Test the command-line interface of check-mailmap.

(Actual .mailmap functionality is already covered by existing tests.)

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fixup! pull: require choice between rebase/merge on non-fast-forward pull

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Cygwin has trustable filemode

The supported Cygwin distribution on supported Windows versions provides
complete support for POSIX filemodes, so enable this by default. git as
distributed by the Cygwin project is configured this way.

This fixes one testsuite failure:
t3300 test 17 (diff-index -M -p with mode change quotes funny filename)

Historical notes: Earlier versions of Cygwin (version 1.5 and prior) had
various methods for supporting posix file modes on different file systems,
often using extended attributes, and this support was optional.  Such
versions of Cygwin are not available on any public mirror and are not
supported by the Cygwin project. The currently available Cygwin supports
POSIX file modes without exception - this is not an optional
configuration. The support does depend upon the underlying file system
(neither Linux nor Cygwin can set an execute bit on a FAT file system as
FAT has no such support), but as this is no different than Linux, the
default should not treat Cygwin differently than Linux.

Users who desire the non-POSIX mode of operation must explicitly set
core.filemode=False, accepting non-interoperability with Linux.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use compat/regex on Cygwin

Cygwin's regex library does not pass git's tests, so don't use it. This
fixes failures in t4018 and t4034.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: allow --no-patch as synonym for -s

This follows the usual convention of having a --no-foo option to negate
--foo.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: allow --patch to override -s/--no-patch

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/git-show.txt: include common diff options, like git-log.txt

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation: move description of -s, --no-patch to diff-options.txt

Technically, "-s, --no-patch" is implemented in diff.c ("git diff
--no-patch" is essentially useless, but valid). From the user point of
view, this allows the documentation to show up in "git show --help",
which is one of the most useful use of the option.

While we're there, add a sentence explaining why the option can be
useful.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/git-log.txt: capitalize section names

This is the convention in other files and even at the beginning of git-log.txt

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
SQUASH??? fixup! diff: allow --patch to override -s/--no-patch

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4203: demonstrate loss of single-character name in mailmap entry

A bug in mailmap.c:parse_name_and_email() causes it to overlook the
single-character name in "A <user@host>" and parse it only as
"<user@host>". Demonstrate this problem.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: do not lose single-letter names

In parse_name_and_email() function, there is this line:

	*name = (nstart < nend ? nstart : NULL);

When the function is given a buffer "A <A@example.org> <old@x.z>",
nstart scans from the beginning of the buffer, skipping whitespaces
(there isn't any, so nstart points at the buffer), while nend starts
from one byte before the first '<' and skips whitespaces backwards
and stops at the first non-whitespace (i.e. it hits "A" at the
beginning of the buffer).  nstart == nend in this case for a
single-letter name, and an off-by-one error makes it fail to pick up
the name, which makes the entry equivalent to

	<A@example.org> <old@x.z>

without the name.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4203: demonstrate loss of uppercase characters in canonical email

The email addresses read from .mailmap are downcased before being
inserted into the mailmap data structure, which undesirably loses
information.  It is impossible, for instance, to map <first.last@host>
to <First.Last@host>. Demonstrate this problem.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: do not downcase mailmap entries

The email addresses in the records read from the .mailmap file are
downcased very early, and then used to match against e-mail
addresses in the input.  Because we do use case insensitive version
of string list to manage these entries, there is no need to do this,
and worse yet, downcasing the rewritten/canonical e-mail read from
the .mailmap file loses information.

Stop doing that, and also make the string list used to keep multiple
names for an mailmap entry case insensitive (the code that uses the
list, lookup_prefix(), expects a case insensitive match).

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: debug: fix out-of-order fprintf() arguments

Resolve segmentation fault due to arguments passed in wrong order.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: debug: fix malformed fprintf() format conversion specification

Resolve segmentation fault due to size_t variable being consumed by
'%s'.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: debug: eliminate -Wformat field precision type warning

The compiler complains that '*' in fprintf() format "%.*s" should
have type int, but we pass size_t. Fix this.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: debug: avoid passing NULL to fprintf() '%s' conversion specification

POSIX does not state the behavior of '%s' conversion when passed a
NULL pointer. Some implementations interpolate literal "(null)";
others may crash.

Callers of debug_mm() often pass NULL as indication of either a
missing name or email address.  Instead, let's always supply a
proper string pointer, and make it a bit more descriptive: "(none)"

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: style fixes

Wrap overlong lines and format the multi-line comments to match our
coding style.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>