t1512: correct leftover constants from earlier edition

The earliest iteration of this test script used a magic string
110282 as the common prefix for ambiguous object names, but the
final edition switched the common prefix to 0000000000 (10 "0"s).

Unfortunately, instances of the original prefix were left in the
comments and a few tests.  Replace them with the correct constants.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_short_sha1(): correctly disambiguate type-limited abbreviation

One test in t1512 that expects a failure incorrectly passed.  The
test prepares a commit whose object name begins with ten "0"s, and
also prepares a tag that points at the commit.  The object name of
the tag also begins with ten "0"s.  There is no other commit-ish
object in the repository whose name begins with such a prefix.

Ideally, in such a repository:

    $ git rev-parse --verify 0000000000^{commit}

should yield that commit.  If 0000000000 is taken as the commit
0000000000e4f, peeling it to a commmit yields that commit itself,
and if 0000000000 is taken as the tag 0000000000f8f, peeling it to a
commit also yields the same commit, so in that twisted sense, the
extended SHA-1 expression 0000000000^{commit} is unambigous.  The
test that expects a failure is to check the above command.

The reason the test expects a failure is that we did not implement
such a "unification" of two candidate objects.  What we did (or at
least, meant to) implement was to recognise that a commit-ish is
required to expand 0000000000, and notice that there are two succh
commit-ish, and diagnose the request as ambiguous.

However, there was a bug in the logic to check the candidate
objects.  When the code saw 0000000000f8f (a tag) that shared the
shortened prefix (ten "0"s), it tried to make sure that the tag is a
commit-ish by looking at the tag object.  Because it incorrectly
used lookup_object() when the tag has not been parsed, however, we
incorrectly declared that the tag is _not_ a commit-ish, leaving the
sole commit in the repository, 0000000000e4f, that has the required
prefix as "unique match", causing the test to pass when it shouldn't.

This fixes the logic to inspect the type of the object a tag refers
to, to make the test that is expected to fail correctly fail.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch-pack: avoid quadratic list insertion in mark_complete

We insert the commit pointed to by each ref one-by-one into
the "complete" commit_list using insert_by_date. Because
each insertion is O(n), we end up with O(n^2) behavior.

This typically doesn't matter, because the number of refs is
reasonably small. And even if there are a lot of refs, they
often point to a smaller set of objects (in which case the
optimization in commit ea5f220 keeps our "n" small).

However, in pathological repositories (hundreds of thousands
of refs, each pointing to a unique commit), this quadratic
behavior can make a difference. Since we do not care about
the list order until we have finished building it, we can
simply keep it unsorted during the insertion phase, then
sort it afterwards.

On a repository like the one described above, this dropped
the time to do a no-op fetch from 2.0s to 1.7s. On normal
repositories, it probably does not matter at all, but it
does not hurt to protect ourselves from pathological cases.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
commit.c: make compare_commits_by_commit_date global

This helper function was introduced as a prio_queue
comparator to help topological sorting. However, other users
of prio_queue who want to replace commit_list_insert_by_date
will want to use it, too. So let's make it public.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch-pack: avoid quadratic behavior in rev_list_push

When we call find_common to start finding common ancestors
with the remote side of a fetch, the first thing we do is
insert the tip of each ref into our rev_list linked list. We
keep the list sorted the whole time with
commit_list_insert_by_date, which means our insertion ends
up doing O(n^2) timestamp comparisons.

We could teach rev_list_push to use an unsorted list, and
then sort it once after we have added each ref. However, in
get_rev, we process the list by popping commits off the
front and adding parents back in timestamp-sorted order. So
that procedure would still operate on the large list.

Instead, we can replace the linked list with a heap-based
priority queue, which can do O(log n) insertion, making the
whole insertion procedure O(n log n).

As a result of switching to the prio_queue struct, we fix
two minor bugs:

  1. When we "pop" a commit in get_rev, and when we clear
     the rev_list in find_common, we do not take care to
     free the "struct commit_list", and just leak its
     memory. With the prio_queue implementation, the memory
     management is handled for us.

  2. In get_rev, we look at the head commit of the list,
     possibly push its parents onto the list, and then "pop"
     the front of the list off, assuming it is the same
     element that we just peeked at. This is typically going
     to be the case, but would not be in the face of clock
     skew: the parents are inserted by date, and could
     potentially be inserted at the head of the list if they
     have a timestamp newer than their descendent. In this
     case, we would accidentally pop the parent, and never
     process it at all.

     The new implementation pulls the commit off of the
     queue as we examine it, and so does not suffer from
     this problem.

With this patch, a fetch of a single commit into a
repository with 50,000 refs went from:

  real    0m7.984s
  user    0m7.852s
  sys     0m0.120s

to:

  real    0m2.017s
  user    0m1.884s
  sys     0m0.124s

Before this patch, a larger case with 370K refs still had
not completed after tens of minutes; with this patch, it
completes in about 12 seconds.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Do not ignore merge options in interactive rebase

Merge strategy and its options can be specified in `git rebase`,
but with `--interactive`, they were completely ignored.

Signed-off-by: Arnaud Fontaine <arnau@debian.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge: handle --ff/--no-ff/--ff-only as a tri-state option

These three options mean "favor fast-forwarding when possible,
without creating an unnecessary merge", "never fast-forward and
always create a merge commit even when the commit being merged is a
strict descendant", and "we do not want to create any merge commit;
update only when the merged commit is a strict descendant".

They are "pick one out of these three possibilities" options, and
correspond to "merge.ff" configuration that is tri-state (yes, no
and only).

However, the implementation did not follow the usual convention for
the command line options (later one wins, and command line overrides
what is in the configuration).

Fix this by consolidating two variables (fast_forward_only and
allow_fast_forward) used in the implementation into one enum that
can take one of the three possible values.

Signed-off-by: Miklos Vajna <vmiklos@suse.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
submodule update: allow custom command to update submodule working tree

Users can set submodule.$name.update to '!command' which will cause
'command' to be run instead of checkout/merge/rebase. This allows
the user finer-grained control over how the update is done.

The primary motivation for this was interoperability with stgit;
however being able to intercept the submodule update process may
prove useful for integrating with or extending other tools.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add --depth to submodule update/add

Add the --depth option to the add and update commands of "git submodule",
which is then passed on to the clone command. This is useful when the
submodule(s) are huge and you're not really interested in anything but
the latest commit.

Tests are added and some indention adjustments were made to conform to the
rest of the testfile on "submodule update can handle symbolic links in pwd".

Signed-off-by: Fredrik Gustafsson <iveqy@iveqy.com>
Acked-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-config: update doc for --get with multiple values

Since commit 00b347d (git-config: do not complain about duplicate
entries, 2012-10-23), "git config --get" does not exit with an error if
there are multiple values for the specified key but instead returns the
last value.  Update the documentation to reflect this.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-remote-mediawiki: un-brace file handles in binmode calls

Commit e83d36b66fc turned "print STDOUT" into "print {*STDOUT}", as
suggested by perlcritic. Unfortunately, it also changed two "binmode
STDOUT" calls the same way, which does not work and yield a "Not a GLOB
reference" error.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
pretty.c: drop const-ness from pretty_print_context

In the current code, callers are expected to fill in the
pretty_print_context, and then the pretty.c functions simply
read from it. This leaves no room for the pretty.c functions
to communicate with each other by manipulating the context
(e.g., data seen while printing the header may impact how we
print the body).

Rather than introduce a new struct to hold modifiable data,
let's just drop the const-ness of the existing context
struct.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
teach format-patch to place other authors into in-body "From"

Format-patch generates emails with the "From" address set to the
author of each patch. If you are going to send the emails, however,
you would want to replace the author identity with yours (if they
are not the same), and bump the author identity to an in-body
header.

Normally this is handled by git-send-email, which does the
transformation before sending out the emails. However, some
workflows may not use send-email (e.g., imap-send, or a custom
script which feeds the mbox to a non-git MUA). They could each
implement this feature themselves, but getting it right is
non-trivial (one must canonicalize the identities by reversing any
RFC2047 encoding or RFC822 quoting of the headers, which has caused
many bugs in send-email over the years).

This patch takes a different approach: it teaches format-patch a
"--from" option which handles the ident check and in-body header
while it is writing out the email.  It's much simpler to do at this
level (because we haven't done any quoting yet), and any workflow
based on format-patch can easily turn it on.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change "remote tracking" to "remote-tracking"

Fix a typo ("remote remote-tracking") going back to the big cleanup
in 2010 (8b3f3f84 etc). Also, remove some more occurrences of
"tracking" and "remote tracking" in favor of "remote-tracking".

Signed-off-by: Michael Schubert <mschub@elegosoft.com>
Reviewed-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'maint-1.8.1' into maint-1.8.2

* maint-1.8.1:
  git-config: update doc for --get with multiple values
Merge branch 'maint-1.8.2' into maint

* maint-1.8.2:
  git-config: update doc for --get with multiple values
Merge branch 'rr/die-on-missing-upstream' into maint

When a reflog notation is used for implicit "current branch", we did
not say which branch, and worse said "branch ''".

* rr/die-on-missing-upstream:
  sha1_name: fix error message for @{<N>}, @{<date>}
  sha1_name: fix error message for @{u}
Merge branch 'cb/log-follow-with-combined' into maint

"git log -c --follow $path" segfaulted upon hitting the commit that
renamed the $path being followed.

* cb/log-follow-with-combined:
  fix segfault with git log -c --follow
Merge branch 'ar/wildmatch-foldcase' into maint

The wildmatch engine did not honor WM_CASEFOLD option correctly.

* ar/wildmatch-foldcase:
  wildmatch: properly fold case everywhere
Merge branch 'cm/gitweb-project-list-persistent-cgi-fix' into maint

"gitweb" forgot to clear a global variable $search_regexp upon each
request, mistakenly carrying over the previous search to a new one
when used as a persistent CGI.

* cm/gitweb-project-list-persistent-cgi-fix:
  gitweb: fix problem causing erroneous project list