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>

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>

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>

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>

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>

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>

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>

Teach commands in the "log" family to optionally pay attention to
the mailmap.

* ap/log-mailmap:
  log --use-mailmap: optimize for cases without --author/--committer search
  log: add log.mailmap configuration option
  log: grep author/committer using mailmap
  test: add test for --use-mailmap option
  log: add --use-mailmap option
  pretty: use mailmap to display username and email
  mailmap: add mailmap structure to rev_info and pp
  mailmap: simplify map_user() interface
  mailmap: remove email copy and length limitation
  Use split_ident_line to parse author and committer
  string-list: allow case-insensitive string list

Simplify map_user(), mostly to avoid copies of string buffers. It
also simplifies caller functions.

map_user() directly receive pointers and length from the commit buffer
as mail and name. If mapping of the user and mail can be done, the
pointer is updated to a new location. Lengths are also updated if
necessary.

The caller of map_user() can then copy the new email and name if
necessary.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

In map_user(), we have email pointer that points at the beginning of
an e-mail address, but the buffer is not terminated with a NUL after
the e-mail address.  It typically has ">" after the address, and it
could have even more if it comes from author/committer line in a
commit object.  Or it may not have ">" after it.

We used to copy the e-mail address proper into a temporary buffer
before asking the string-list API to find the e-mail address in the
mailmap, because string_list_lookup() function only takes a NUL
terminated full string.

Introduce a helper function lookup_prefix that takes the email
pointer and the length, and finds a matching entry in the string
list used for the mailmap, by doing the following:

 - First ask string_list_find_insert_index() where in its sorted
   list the e-mail address we have (including the possible trailing
   junk ">...") would be inserted.

 - It could find an exact match (e.g. we had a clean e-mail address
   without any trailing junk).  We can return the item in that case.

 - Or it could return the index of an item that sorts after the
   e-mail address we have.

 - If we did not find an exact match against a clean e-mail address,
   then the record we are looking for in the mailmap has to exist
   before the index returned by the function (i.e. "email>junk"
   always sorts later than "email").  Iterate, starting from that
   index, down the map->items[] array until we find the exact record
   we are looking for, or we see a record with a key that definitely
   sorts earlier than the e-mail we are looking for (i.e. when we
   are looking for "email" in "email>junk", a record in the mailmap
   that begins with "emaik" strictly sorts before "email", if such a
   key existed in the mailmap).

This, together with the earlier enhancement to support
case-insensitive sorting, allow us to remove an extra copy of email
buffer to downcase it.

A part of this is based on Antoine Pelisse's previous work.

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