Add IPv6 support by implementing name resolution with the
protocol agnostic getaddrinfo(3) API. The old gethostbyname(3)
code is still available when git is compiled with NO_IPV6.
Signed-off-by: NElia Pinto <gitter.spiros@gmail.com>
Helped-by: NJeff King <peff@peff.net>
Helped-by: NEric Sunshine <sunshine@sunshineco.com>
Signed-off-by: NJeff King <peff@peff.net>

Many of the date functions write into fixed-size buffers.
This is a minor pain, as we have to take special
precautions, and frequently end up copying the result into a
strbuf or heap-allocated buffer anyway (for which we
sometimes use strcpy!).

Let's instead teach parse_date, datestamp, etc to write to a
strbuf. The obvious downside is that we might need to
perform a heap allocation where we otherwise would not need
to. However, it turns out that the only two new allocations
required are:

  1. In test-date.c, where we don't care about efficiency.

  2. In determine_author_info, which is not performance
     critical (and where the use of a strbuf will help later
     refactoring).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When the user has no ~/.gitconfig file, git config --global --edit used
to launch an editor on an nonexistant file name.

Instead, create a file with a default content before launching the
editor. The template contains only commented-out entries, to save a few
keystrokes for the user. If the values are guessed properly, the user
will only have to uncomment the entries.

Advanced users teaching newbies can create a minimalistic configuration
faster for newbies. Beginners reading a tutorial advising to run "git
config --global --edit" as a first step will be slightly more guided for
their first contact with Git.
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Split_ident currently parses left to right. Given this
input:

  Your Name <email@example.com> 123456789 -0500\n

We assume the name starts the line and runs until the first
"<".  That starts the email address, which runs until the
first ">".  Everything after that is assumed to be the
timestamp.

This works fine in the normal case, but is easily broken by
corrupted ident lines that contain an extra ">". Some
examples seen in the wild are:

  1. Name <email>-<> 123456789 -0500\n

  2. Name <email> <Name<email>> 123456789 -0500\n

  3. Name1 <email1>, Name2 <email2> 123456789 -0500\n

Currently each of these produces some email address (which
is not necessarily the one the user intended) and end up
with a NULL date (which is generally interpreted as the
epoch by "git log" and friends).

But in each case we could get the correct timestamp simply
by parsing from the right-hand side, looking backwards for
the final ">", and then reading the timestamp from there.

In general, it's a losing battle to try to automatically
guess what the user meant with their broken crud. But this
particular workaround is probably worth doing.  One, it's
dirt simple, and can't impact non-broken cases. Two, it
doesn't catch a single breakage we've seen, but rather a
large class of errors (i.e., any breakage inside the email
angle brackets may affect the email, but won't spill over
into the timestamp parsing). And three, the timestamp is
arguably more valuable to get right, because it can affect
correctness (e.g., in --until cutoffs).

This patch implements the right-to-left scheme described
above. We adjust the tests in t4212, which generate a commit
with such a broken ident, and now gets the timestamp right.
We also add a test that fsck continues to detect the
breakage.

For reference, here are pointers to the breakages seen (as
numbered above):

[1] http://article.gmane.org/gmane.comp.version-control.git/221441

[2] http://article.gmane.org/gmane.comp.version-control.git/222362

[3] http://perl5.git.perl.org/perl.git/commit/13b79730adea97e660de84bbe67f9d7cbe344302Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Commit a9080475 taught format-patch the "--from" option,
which places the author ident into an in-body from header,
and uses the committer ident in the rfc822 from header.  The
documentation claims that it will omit the in-body header
when it is the same as the rfc822 header, but the code never
implemented that behavior.

This patch completes the feature by comparing the two idents
and doing nothing when they are the same (this is the same
as simply omitting the in-body header, as the two are by
definition indistinguishable in this case). This makes it
reasonable to turn on "--from" all the time (if it matches
your particular workflow), rather than only using it when
exporting other people's patches.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

An earlier conversion from fgets() to strbuf_getline() in the
codepath to read from /etc/mailname to learn the default host-part
of the ident e-mail address forgot that strbuf_getline() stores the
line at the beginning of the buffer just like fgets().

The "username@" the caller has prepared in the strbuf, expecting the
function to append the host-part to it, was lost because of this.
Reported-by: NMihai Rusu <dizzy@google.com>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Acked-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We keep track of whether the user ident was given to us
explicitly, or if we guessed at it from system parameters
like username and hostname. However, we kept only a single
variable. This covers the common cases (because the author
and committer will usually come from the same explicit
source), but can miss two cases:

  1. GIT_COMMITTER_* is set explicitly, but we fallback for
     GIT_AUTHOR. We claim the ident is explicit, even though
     the author is not.

  2. GIT_AUTHOR_* is set and we ask for author ident, but
     not committer ident. We will claim the ident is
     implicit, even though it is explicit.

This patch uses two variables instead of one, updates both
when we set the "fallback" values, and updates them
individually when we read from the environment.

Rather than keep user_ident_sufficiently_given as a
compatibility wrapper, we update the only two callers to
check the committer_ident, which matches their intent and
what was happening already.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In v1.5.6-rc0~56^2 (2008-05-04) "user_ident_explicitly_given"
was introduced as a global for communication between config,
ident, and builtin-commit.  In v1.7.0-rc0~72^2 (2010-01-07)
readers switched to using the common wrapper
user_ident_sufficiently_given().  After v1.7.11-rc1~15^2~18
(2012-05-21), the var is only written in ident.c.

Now we can make it static, which will enable further
refactoring without worrying about upsetting other code.
Signed-off-by: NJeff King <peff@peff.net>
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

Commits made by ancient version of Git allowed committer without
human readable name, like this (00213b17c in the kernel history):

    tree 6947dba41f8b0e7fe7bccd41a4840d6de6a27079
    parent 352dd1df32e672be4cff71132eb9c06a257872fe
    author Petr Baudis <pasky@ucw.cz> 1135223044 +0100
    committer  <sam@mars.ravnborg.org> 1136151043 +0100

    kconfig: Remove support for lxdialog --checklist

    ...
Signed-off-by: NPetr Baudis <pasky@suse.cz>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

When fed such a commit, --format='%ci' fails to parse it, and gives
back an empty string.  Update the split_ident_line() to be a bit
more lenient when parsing, but make sure the caller that wants to
pick up sane value from its return value does its own validation.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If we come up with a hostname like "foo.(none)" because the
user's machine is not fully qualified, we should reject this
in strict mode (e.g., when we are making a commit object),
just as we reject an empty gecos username.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Callers who ask for ERROR_ON_NO_NAME are not so much
concerned that the name will be blank (because, after all,
we will fall back to using the username), but rather it is a
check to make sure that low-quality identities do not end up
in things like commit messages or emails (whereas it is OK
for them to end up in things like reflogs).

When future commits add more quality checks on the identity,
each of these callers would want to use those checks, too.
Rather than modify each of them later to add a new flag,
let's refactor the flag.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Most callers want to see all of "$name <$email> $date", but
a few want only limited parts, omitting the date, or even
the name. We already have IDENT_NO_DATE to handle the date
part, but there's not a good option for getting just the
email. Callers have to done one of:

  1. Call ident_default_email; this does not respect
     environment variables, nor does it promise to trim
     whitespace or other crud from the result.

  2. Call git_{committer,author}_info; this returns the name
     and email, leaving the caller to parse out the wanted
     bits.

This patch adds IDENT_NO_NAME; it stops short of adding
IDENT_NO_EMAIL, as no callers want it (nor are likely to),
and it complicates the error handling of the function.

When no name is requested, the angle brackets (<>) around
the email address are also omitted.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As a short-hand, we extract this flag into the local
variable "name_addr_only". It's more accurate to simply
negate this and refer to it as "want_date", which will be
less confusing when we add more NO_* flags.

While we're touching this part of the code, let's move the
call to ident_default_date() only when we are actually going
to use it, not when we have NO_DATE set, or when we get a
date from the environment.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There's on point in printing the name, since it is by
definition the empty string if we have reached this code
path. Instead, let's be more clear that we are complaining
about the empty name, but still show the email address that
it is attached to (since that may provide some context to
the user).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Commit 4b340cfa split the logic to parse an ident line out of
pretty.c's format_person_part. But in doing so, it
accidentally introduced an off-by-one error that caused it
to think that single-character names were invalid.

This manifested itself as the "%an" format failing to show
anything at all for a single-character name.
Reported-by: NBrian Turner <bturner@atlassian.com>
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Usually these values get fed to fmt_ident, which will trim
any cruft anyway, but there are a few code paths which use
them directly. Let's clean them up for the benefit of those
callers. Furthermore, fmt_ident will look at the pre-trimmed
value and decide whether to invoke ERROR_ON_NO_NAME; this
check can be fooled by a name consisting only of spaces.

Note that we only bother to clean up when we are pulling the
information from gecos or from system files. Any other value
comes from a config file, where we will have cleaned up
accidental whitespace already.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Now that we accept arbitrary-sized names and email
addresses, the only remaining limit is in the actual
formatting of the names into a buffer. The current limit is
1000 characters, which is not likely to be reached, but
using a strbuf is one less error condition we have to worry
about.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we construct an email address from the username and
hostname, we generate the host part of the email with this
procedure:

  1. add the result of gethostname

  2. if it has a dot, ok, it's fully qualified

  3. if not, then look up the unqualified hostname via
     gethostbyname; take the domain name of the result and
     append it to the hostname

Step 3 can actually produce a bogus result, as the name
returned by gethostbyname may not be related to the hostname
we fed it (e.g., consider a machine "foo" with names
"foo.one.example.com" and "bar.two.example.com"; we may have
the latter returned and generate the bogus name
"foo.two.example.com").

This patch simply uses the full hostname returned by
gethostbyname. In the common case that the first part is the
same as the unqualified hostname, the behavior is identical.
And in the case that it is not the same, we are much more
likely to be generating a valid name.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When getpwuid fails, we give a cute but cryptic message.
While it makes sense if you know that getpwuid or identity
functions are being called, this code is triggered behind
the scenes by quite a few git commands these days (e.g.,
receive-pack on a remote server might use it for a reflog;
the current message is hard to distinguish from an
authentication error).  Let's switch to something that gives
a little more context.

While we're at it, we can factor out all of the
cut-and-pastes of the "you don't exist" message into a
wrapper function. Rather than provide xgetpwuid, let's make
it even more specific to just getting the passwd entry for
the current uid. That's the only way we use getpwuid anyway,
and it lets us make an even more specific error message.

The current message also fails to mention errno. While the
usual cause for getpwuid failing is that the user does not
exist, mentioning errno makes it easier to diagnose these
problems.  Note that POSIX specifies that errno remain
untouched if the passwd entry does not exist (but will be
set on actual errors), whereas some systems will return
ENOENT or similar for a missing entry. We handle both cases
in our wrapper.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we pull the user's name from the GECOS field of the
passwd file (or generate an email address based on their
username and hostname), we put the result into a
static buffer. While it's extremely unlikely that anybody
ever hit these limits (after all, in such a case their
parents must have hated them), we still had to deal with the
error cases in our code.

Converting these static buffers to strbufs lets us simplify
the code and drop some error messages from the documentation
that have confused some users.

The conversion is mostly mechanical: replace string copies
with strbuf equivalents, and access the strbuf.buf directly.
There are a few exceptions:

  - copy_gecos and copy_email are the big winners in code
    reduction (since they no longer have to manage the
    string length manually)

  - git_ident_config wants to replace old versions of
    the default name (e.g., if we read the config multiple
    times), so it must reset+add to the strbuf instead of
    just adding

Note that there is still one length limitation: the
gethostname interface requires us to provide a static
buffer, so we arbitrarily choose 1024 bytes for the
hostname.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The fmt_ident function gets a flag that tells us whether to
die if the name field is blank. If it is blank and we don't
die, then we fall back to the username from the passwd file.

The current code writes the value into git_default_name.
However, that's not necessarily correct, as the empty value
might have come from git_default_name, or it might have been
passed in.  This leads to two potential problems:

  1. If we are overriding an empty name in the passed-in
     value, then we may be overwriting a perfectly good name
     (from gitconfig or gecos) in the git_default_name
     buffer. Later calls to fmt_ident will end up using the
     fallback name, even though a better name was available.

  2. If we override an empty gecos name, we end up with the
     fallback name in git_default_name. A later call that
     uses IDENT_ERROR_ON_NO_NAME will see the fallback name
     and think that it is a good name, instead of producing
     an error. In other words, a blank gecos name would
     cause an error with this code:

       git_committer_info(IDENT_ERROR_ON_NO_NAME);

     but not this:

       git_committer_info(0);
       git_committer_info(IDENT_ERROR_ON_NO_NAME);

     because in the latter case, the first call has polluted
     the name buffer.

Instead, let's make the fallback a per-invocation variable.
We can just use the pw->pw_name string directly, since it
only needs to persist through the rest of the function (and
we don't do any other getpwent calls).

Note that while this solves (1) for future invocations of
fmt_indent, the current invocation might use the fallback
when it could in theory load a better value from
git_default_name. However, by not passing
IDENT_ERROR_ON_NO_NAME, the caller is indicating that it
does not care too much about the name, anyway, so we don't
bother; this is primarily about protecting future callers
who do care.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There are no more callers who want this, so we can drop it.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We use fgets to read the /etc/mailname file, which means we
will typically end up with an extra newline in our
git_default_email. Most of the time this doesn't matter, as
fmt_ident will skip it as cruft, but there is one code path
that accesses it directly (in http-push.c:lock_remote).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There's no reason anybody outside of ident.c should access
these directly (they should use the new accessors which make
sure the variables are initialized), so we can make them
file-scope statics.

While we're at it, move user_ident_explicitly_given into
ident.c; while still globally visible, it makes more sense
to reside with the ident code.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There's no reason for this to be in config, except that once
upon a time all of the config parsing was there. It makes
more sense to keep the ident code together.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This function sets up the default name, email, and date, and
is not publicly available. Let's split it into three public
functions so that callers can get just the parts they need.

While we're at it, let's change the interface to simple
accessors. The original function was called only by fmt_ident,
and contained logic for "if we already have some other
value, don't load the default" which properly belongs in
fmt_ident.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The commit formatting logic format_person_part() in pretty.c
implements the logic to split an author/committer ident line into
its parts, intermixed with logic to compute its output using these
piece it computes.

Separate the former out to a helper function split_ident_line() so
that other codepath can use the same logic, and rewrite the function
using the helper function.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Avoid a getpwuid() call (which contacts the network if the password
database is not local), read of /etc/mailname, gethostname() call, and
reverse DNS lookup if the user has already chosen a name and email
through configuration, the environment, or the command line.

This should slightly speed up commands like "git commit".  More
importantly, it improves error reporting when computation of the
default ident string does not go smoothly.  For example, after
detecting a problem (e.g., "warning: cannot open /etc/mailname:
Permission denied") in retrieving the default committer identity:

	touch /etc/mailname;	# as root
	chmod -r /etc/mailname;	# as root
	git commit -m 'test commit'

you can squelch the warning while waiting for your sysadmin to fix the
permissions problem.

	echo '[user] email = me@example.com' >>~/.gitconfig
Inspired-by: NJohannes Sixt <j6t@kdgb.org>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Before falling back to gethostname(), check /etc/mailname if
GIT_AUTHOR_EMAIL is not set in the environment or through config
files.  Only fall back if /etc/mailname cannot be opened or read.

The /etc/mailname convention comes from Debian policy section 11.6
("mail transport, delivery and user agents"), though maybe it could be
useful sometimes on other machines, too.  The lack of this support was
noticed by various people in different ways:

 - Ian observed that git was choosing the address
   'ian@anarres.relativity.greenend.org.uk' rather than
   'ian@davenant.greenend.org.uk' as it should have done.

 - Jonathan noticed that operations like "git commit" were needlessly
   slow when using a resolver that was slow to handle reverse DNS
   lookups.

Alas, after this patch, if /etc/mailname is set up and the [user] name
and email configuration aren't, the committer email will not provide a
charming reminder of which machine commits were made on any more.  But
I think it's worth it.

Mechanics: the functionality of reading mailname goes in its own
function, so people who care about other distros can easily add an
implementation to a similar location without making copy_email() too
long and losing clarity.  While at it, we split out the fallback
default logic that does gethostname(), too (rearranging it a little
and adding a check for errors from gethostname while at it).

Based on a patch by Gerrit Pape <pape@smarden.org>.
Requested-by: NIan Jackson <ijackson@chiark.greenend.org.uk>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Improved-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Allow NO_GECOS_IN_PWENT to be defined in the Makefile for platforms that
lack the pw_gecos field in their "struct passwd", in which case the
uppercased user name is used instead via the standard '&' replacement
mechanism.
Signed-off-by: NRafael Gieschke <rafael@gieschke.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

nlen has to be added to len when inserting (capitalized) pw_name as
substitution for "&" in pw_gecos. Otherwise, pw_gecos will be truncated
and data might be written beyond name+sz.
Signed-off-by: NRafael Gieschke <rafael@gieschke.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If the user gives "git commit --date=foobar", we silently
ignore the --date flag. We should note the error.

This patch puts the fix at the lowest level of fmt_ident,
which means it also handles GIT_AUTHOR_DATE=foobar, as well.

There are two down-sides to this approach:

  1. Technically this breaks somebody doing something like
     "git commit --date=now", which happened to work because
     bogus data is the same as "now". Though we do
     explicitly handle the empty string, so anybody passing
     an empty variable through the environment will still
     work.

     If the error is too much, perhaps it can be downgraded
     to a warning?

  2. The error checking happens _after_ the commit message
     is written, which can be annoying to the user. We can
     put explicit checks closer to the beginning of
     git-commit, but that feels a little hack-ish; suddenly
     git-commit has to care about how fmt_ident works. Maybe
     we could simply call fmt_ident earlier?
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Compiling today's pu gave
    ...
    CC ident.o
    CC levenshtein.o
ident.c: In function 'fmt_ident':
ident.c:206: warning: format not a string literal and no format arguments
    CC list-objects.o
    ...

This warning seems to have appeared first in 18e95f27 (ident.c:
remove unused variables) which removed additional fprintf arguments.

Suppress this warning by using fputs instead of fprintf.
Signed-off-by: NTarmigan Casebolt <tarmigan+git@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

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

The environment variable EMAIL has been honored since 28a94f88 (Fall back
to $EMAIL for missing GIT_AUTHOR_EMAIL and GIT_COMMITTER_EMAIL,
2007-04-28) as the end-user's wish to use the address as the identity.
When we use it, we should say we are explicitly given email by the user.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

bb1ae3f6 (commit: Show committer if automatic, 2008-05-04) added a logic to
check both name and email were given explicitly by the end user, but it
assumed that fmt_ident() is never called before git_default_user_config()
is called, which was fragile.  The former calls setup_ident() and fills
the "default" name and email, so the check in the config parser would have
mistakenly said both are given even if only user.name was provided.

Make the logic more robust by keeping track of name and email separately.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Acked-by: NSanti Béjar <santi@agolina.net>

d5cc2de9 (ident.c: Trim hint printed when gecos is empty., 2006-11-28)
reworded the message used as printf() format and dropped "%s" from it;
these two variables that hold the names of GIT_{AUTHOR,COMMITTER}_NAME
environment variables haven't been used since then.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

For scripts using "git var -l" to read all logical variables at
once, not all per-variable warnings will be relevant.  So suppress
them.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>