Documentation: avoid poor-man's small caps

In the earlier days, we used to spell the name of the system as GIT,
to simulate as if it were typeset with capital G and IT in small
caps.  Later we stopped doing so at around 1.6.5 days.

Let's stop doing so throughout the documentation.  The name to refer
to the whole system (and the concept it embodies) is "Git"; the
command end-users type is "git".  And document this in the coding
guideline.

Signed-off-by: Thomas Ackermann <th.acker@arcor.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change 'git' to 'Git' whenever the whole system is referred to #1

Signed-off-by: Thomas Ackermann <th.acker@arcor.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fixup! Change 'git' to 'Git' whenever the whole system is referred to #1
fixup! fixup! Change 'git' to 'Git' whenever the whole system is referred to #1
Change 'git' to 'Git' whenever the whole system is referred to #2

Signed-off-by: Thomas Ackermann <th.acker@arcor.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fixup! Change 'git' to 'Git' whenever the whole system is referred to #2
Change 'git' to 'Git' whenever the whole system is referred to #3

Signed-off-by: Thomas Ackermann <th.acker@arcor.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fixup! Change 'git' to 'Git' whenever the whole system is referred to #3
Change 'git' to 'Git' whenever the whole system is referred to #4

Signed-off-by: Thomas Ackermann <th.acker@arcor.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fixup! Change 'git' to 'Git' whenever the whole system is referred to #4
config: add helper function for parsing key names

The config callback functions get keys of the general form:

  section.subsection.key

(where the subsection may be contain arbitrary data, or may
be missing). For matching keys without subsections, it is
simple enough to call "strcmp". Matching keys with
subsections is a little more complicated, and each callback
does it in an ad-hoc way, usually involving error-prone
pointer arithmetic.

Let's provide a helper that keeps the pointer arithmetic all
in one place.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
archive-tar: use parse_config_key when parsing config

This is fewer lines of code, but more importantly, fixes a
bogus pointer offset. We are looking for "tar." in the
section, but later assume that the dot we found is at offset
9, not 3. This is a holdover from an earlier iteration of
767cf45 which called the section "tarfilter".

As a result, we could erroneously reject some filters with
dots in their name, as well as read uninitialized memory.

Reported by (and test by) René Scharfe.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
convert some config callbacks to parse_config_key

These callers can drop some inline pointer arithmetic and
magic offset constants, making them more readable and less
error-prone (those constants had to match the lengths of
strings, but there is no automatic verification of that
fact).

The "ep" pointer (presumably for "end pointer"), which
points to the final key segment of the config variable, is
given the more standard name "key" to describe its function
rather than its derivation.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
userdiff: drop parse_driver function

When we parse userdiff config, we generally assume that

  diff.name.key

will affect the "key" value of the "name" driver. However,
without confirming that the key is a valid userdiff key, we
may accidentally conflict with the ancient "diff.color.*"
namespace. The current code is careful not to even create a
driver struct if we do not see a key that is known by the
diff-driver code.

However, this carefulness is unnecessary; the default driver
with no keys set behaves exactly the same as having no
driver at all. We can simply set up the driver struct as
soon as we see we have a config key that looks like a
driver. This makes the code a bit more readable.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
submodule: use parse_config_key when parsing config

This makes the code a lot simpler to read by dropping a
whole bunch of constant offsets.

As a bonus, it means we also feed the whole config variable
name to our error functions:

  [before]
  $ git -c submodule.foo.fetchrecursesubmodules=bogus checkout
  fatal: bad foo.fetchrecursesubmodules argument: bogus

  [after]
  $ git -c submodule.foo.fetchrecursesubmodules=bogus checkout
  fatal: bad submodule.foo.fetchrecursesubmodules argument: bogus

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
submodule: simplify memory handling in config parsing

We keep a strbuf for the name of the submodule, even though
we only ever add one string to it. Let's just use xmemdupz
instead, which is slightly more efficient and makes it
easier to follow what is going on.

Unfortunately, we still end up having to deal with some
memory ownership issues in some code branches, as we have to
allocate the string in order to do a string list lookup, and
then only sometimes want to hand ownership of that string
over to the string_list. Still, making that explicit in the
code (as opposed to sometimes detaching the strbuf, and then
always releasing it) makes it a little more obvious what is
going on.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
help: use parse_config_key for man config

The resulting code ends up about the same length, but it is
a little more self-explanatory. It now explicitly documents
and checks the pre-condition that the incoming var starts
with "man.", and drops the magic offset "4".

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
reflog: use parse_config_key in config callback

This doesn't save any lines, but does keep us from doing
error-prone pointer arithmetic with constants.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
push: further simplify the logic to assign rejection reason

First compute the reason why this push would fail if done without
"--force", and then fail it by assigning that reason when the push
was not forced (or if there is no reason to require force, allow it
to succeed).

Record the fact that the push was forced in the forced_update field
only when the push would have failed without the option.

The code becomes shorter, less repetitive and easier to read this
way, especially given that the set of rejection reasons will be
extended in a later patch.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
push: introduce REJECT_FETCH_FIRST and REJECT_NEEDS_FORCE

When we push to update an existing ref, if:

 * the object at the tip of the remote is not a commit; or
 * the object we are pushing is not a commit,

it won't be correct to suggest to fetch, integrate and push again,
as the old and new objects will not "merge".  We should explain that
the push must be forced when there is a non-committish object is
involved in such a case.

If we do not have the current object at the tip of the remote, we do
not even know that object, when fetched, is something that can be
merged.  In such a case, suggesting to pull first just like
non-fast-forward case may not be technically correct, but in
practice, most such failures are seen when you try to push your work
to a branch without knowing that somebody else already pushed to
update the same branch since you forked, so "pull first" would work
as a suggestion most of the time.  And if the object at the tip is
not a commit, "pull first" will fail, without making any permanent
damage.  As a side effect, it also makes the error message the user
will get during the next "push" attempt easier to understand, now
the user is aware that a non-commit object is involved.

In these cases, the current code already rejects such a push on the
client end, but we used the same error and advice messages as the
ones used when rejecting a non-fast-forward push, i.e. pull from
there and integrate before pushing again.

Introduce new rejection reasons and reword the messages
appropriately.

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