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>
t9902: fix 'test A == B' to use = operator

The == operator as an alias to = is not POSIX.  This doesn't actually
matter for the execution of the script, because it only runs when the
shell is bash.  However, it trips up test-lint, so it's nicer to use
the standard form.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
test-lint: detect 'export FOO=bar'

Some shells do not understand the one-line construct, and instead need

  FOO=bar &&
  export FOO

Detect this in the test-lint target.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cache.h: move remote/connect API out of it

The definition of "struct ref" in "cache.h", a header file so
central to the system, always confused me.  This structure is not
about the local ref used by sha1-name API to name local objects.

It is what refspecs are expanded into, after finding out what refs
the other side has, to define what refs are updated after object
transfer succeeds to what values.  It belongs to "remote.h" together
with "struct refspec".

While we are at it, also move the types and functions related to the
Git transport connection to a new header file connect.h

Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/push.c: use OPT_BOOL, not OPT_BOOLEAN

The command line parser of "git push" for "--tags", "--delete", and
"--thin" options still used outdated OPT_BOOLEAN.  Because these
options do not give escalating levels when given multiple times,
they should use OPT_BOOL.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
name-rev: allow converting the exact object name at the tip of a ref

"git name-rev" is supposed to convert given object names into
strings that name the same objects based on refs, that can be fed to
"git rev-parse" to get the same object names back, so the output for
the commit object v1.8.3^0 (i.e. the commit tagged as v1.8.3)

    $ git rev-parse v1.8.3 v1.8.3^0 | git name-rev --stdin
    8af06057d0c31a24e8737ae846ac2e116e8bafb9
    edca4152560522a431a51fc0a06147fc680b5b18 (tags/v1.8.3^0)

has to have "^0" at the end, as "edca41" is a commit, not the tag
that references it.  But we do not get anything for the tag object
(8af0605) itself.

This is because the command however did not bother to see if the
object is at the tip of some ref, and failed to convert a tag
object.

Teach it to show this instead:

    $ git rev-parse v1.8.3 v1.8.3^0 | git name-rev --stdin
    8af06057d0c31a24e8737ae846ac2e116e8bafb9 (tags/v1.8.3)
    edca4152560522a431a51fc0a06147fc680b5b18 (tags/v1.8.3^0)

Signed-off-by: Junio C Hamano <gitster@pobox.com>
describe: use argv-array

Instead of using a hand allocated args[] array, use argv-array API
to manage the dynamically created list of arguments when invoking
name-rev.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
commit: reject non-characters

Unicode clause D14 defines all characters U+nFFFE and U+nFFFF (where
0 <= n <= 10h) as well as the range U+FDD0..U+FDEF as non-characters,
reserved for internal use only.  Disallow these characters in commit
messages as they are normally not recommended for interchange.

Signed-off-by: Peter Krefting <peter@softwolves.pp.se>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert "struct cache_entry *" to "const ..." wherever possible

I attempted to make index_state->cache[] a "const struct cache_entry **"
to find out how existing entries in index are modified and where. The
question I have is what do we do if we really need to keep track of on-disk
changes in the index. The result is

 - diff-lib.c: setting CE_UPTODATE

 - name-hash.c: setting CE_HASHED

 - preload-index.c, read-cache.c, unpack-trees.c and
   builtin/update-index: obvious

 - entry.c: write_entry() may refresh the checked out entry via
   fill_stat_cache_info(). This causes "non-const struct cache_entry
   *" in builtin/apply.c, builtin/checkout-index.c and
   builtin/checkout.c

 - builtin/ls-files.c: --with-tree changes stagemask and may set
   CE_UPDATE

Of these, write_entry() and its call sites are probably most
interesting because it modifies on-disk info. But this is stat info
and can be retrieved via refresh, at least for porcelain
commands. Other just uses ce_flags for local purposes.

So, keeping track of "dirty" entries is just a matter of setting a
flag in index modification functions exposed by read-cache.c. Except
unpack-trees, the rest of the code base does not do anything funny
behind read-cache's back.

The actual patch is less valueable than the summary above. But if
anyone wants to re-identify the above sites. Applying this patch, then
this:

    diff --git a/cache.h b/cache.h
    index 430d021..1692891 100644
    --- a/cache.h
    +++ b/cache.h
    @@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode)
     #define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)

     struct index_state {
    -	struct cache_entry **cache;
    +	const struct cache_entry **cache;
     	unsigned int version;
     	unsigned int cache_nr, cache_alloc, cache_changed;
     	struct string_list *resolve_undo;

will help quickly identify them without bogus warnings.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4211: fix broken test when one -L range is subset of another

t4211 attempts to test multiple git-log -L ranges where one range is a
superset of the other, and falsely succeeds because its "expected"
output is incorrect.

Overlapping -L ranges handed to git-log are coalesced by
line-log.c:sort_and_merge_range_set() into a set of non-overlapping,
disjoint ranges. When one range is a subset of another,
sort_and_merge_range_set() should coalesce both ranges to the superset
range, but instead the coalesced range often is incorrectly truncated to
the end of the subset range. For example, ranges 2-8 and 3-4 are
coalesced incorrectly to 2-4.

One can observe this incorrect behavior with git-log -L using the test
repository created by t4211. The superset/subset ranges t4211 employs
are 4-$ and 8-12 (where $ represents end-of-file). The coalesced range
should be 4-$. Manually invoking git-log with the same ranges the test
employs, we see:

  % git log -L 4:a.c simple |
    awk '/^commit [0-9a-f]{40}/ { print substr($2,1,7) }'
  4659538
  100b61a
  39b6eb2
  a6eb826
  f04fb20
  de4c48a

  % git log -L 8,12:a.c simple | awk ...
  f04fb20
  de4c48a

  % git log -L 4:a.c -L 8,12:a.c simple | awk ...
  a6eb826
  f04fb20
  de4c48a

This last output is incorrect. 8-12 is a subset of 4-$, hence the output
of the coalesced range should be the same as the 4-$ output shown first.
In fact, the above incorrect output is the truncated bogus range 4-12:

  % git log -L 4,12:a.c simple | awk ...
  a6eb826
  f04fb20
  de4c48a

Fix the test to correctly fail in the presence of the
sort_and_merge_range_set() coalescing bug. Do so by changing the
"expected" output to the commits mentioned in the 4-$ output above.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
range_set: fix coalescing bug when range is a subset of another

When coalescing ranges, sort_and_merge_range_set() unconditionally
assumes that the end of a range being folded into a preceding range
should become the end of the coalesced range. This assumption, however,
is invalid when one range is a subset of another.  For example, given
ranges 1-5 and 2-3 added via range_set_append_unsafe(),
sort_and_merge_range_set() incorrectly coalesces them to range 1-3
rather than the correct union range 1-5. Fix this bug.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-http: use argv-array

Instead of using a hand-managed argument array, use argv-array API
to manage dynamically formulated command line.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
push: beginning of compare-and-swap "force/delete safety"

This teaches the deepest part of the callchain for "git push" (and
"git send-pack") to optionally allow "the old value of the ref must
be this, otherwise fail this push" we discussed earlier.

Nobody sets the new "expect_old_sha1" and "expect_old_no_trackback"
bitfields yet, so this is still a no-op.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote.c: add command line option parser for --lockref

Update "git push" and "git send-pack" to parse this commnd line
option.

The intended sematics is:

 * "--lockref" alone, without specifying the details, will protect
   _all_ remote refs that are going to be updated by requiring their
   current value to be the same as the remote-tracking branch we
   have for them, unless otherwise specified;

 * "--lockref=refname", without specifying the expected value, will
   protect that refname, if it is going to be updated, by requiring
   its current value to be the same as the remote-tracking branch we
   have for it;

 * "--lockref=refname:value" will protect that refname, if it is
   going to be updated, by requiring its current value to be the
   same as the specified value (which is allowed to be different
   from the remote-tracking branch we have for the refname, or we do
   not even have to have such a remote-tracking branch when this
   form is used);

 * "--lockref=refname:" (empty value) is to expect that refname does
   not exist (yet); and

 * "--no-lockref" will cancel all the previous --lockref on the
   command line.

In any of the forms, when we try to use a remote-tracking branch for
the remote ref being updated, it is an error if there is no such
remote-tracking branch on our end.

Because the command line options are parsed _before_ we know which
remote we are pushing to, there needs further processing to the
parsed data after we instantiate the transport object to:

 * expand "refname" given by the user to a full refname to be
   matched with the list of "struct ref" used in match_push_refs()
   and set_ref_status_for_push(); and

 * learning the actual local ref that is the remote-tracking branch
   for the specified remote ref.

Further, some processing need to be deferred until we find the set
of remote refs and match_push_refs() returns in order to find the
ones that need to be checked after explicit ones have been processed
for "--lockref" (no specific details).

These post-processing will be the topic of the next patch.

Oh, of course, the option name is still not cast in stone.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
push --lockref: implement logic to populate old_sha1_expect[]

This plugs the push_cas_option data collected by the command line
option parser to the transport system with a new function
apply_push_cas(), which is called after match_push_refs() has
already been called.  At this point, we know which remote we are
talking to, and what remote refs we are going to update, so we can
fill in the details that may have been missing from the command
line, such as

 (1) what abbreviated refname the user gave us matches the actual
     refname at the remote; and

 (2) which remote tracking branch in our local repository to read the
     value of the object to expect at the remote.

to populate the old_sha1_expect[] field of each of the remote ref.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t5533: test "push --lockref"

Prepare two repositories, src and dst, the latter of which is a
clone of the former (with tracking branches), and push from the
latter into the former, using --lockref=name (using tracking ref for
"name" when updating "name"), --lockref=name:value, --lockref=name:
(i.e. check creation), and --lockref (using tracking ref for
anything that we update).

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

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jc/triangle-push-fixup' into jch

Earlier remote.pushdefault (and per-branch branch.*.pushremote)
were introduced as an additional mechanism to choose what
repository to push into when "git push" did not say it from the
command line, to help people who push to a repository that is
different from where they fetch from.  This attempts to finish that
topic by teaching the default mechanism to choose branch in the
remote repository to be updated by such a push.

The 'current', 'matching' and 'nothing' modes (specified by the
push.default configuration variable) extend to such a "triangular"
workflow naturally, but 'upstream' and 'simple' have to be updated.

. 'upstream' is about pushing back to update the branch in the
remote repository that the current branch fetches from and
integrates with, it errors out in a triangular workflow.

. 'simple' is meant to help new people by avoiding mistakes, and
will be the safe default in Git 2.0.  In a non-triangular
workflow, it will continue to act as a cross between 'upstream'
and 'current' in that it pushes to the current branch's
@{upstream} only when it is set to the same name as the current
branch (e.g. your 'master' forks from the 'master' from the
central repository).  In a triangular workflow, this series
tentatively defines it as the same as 'current', but we may have
to tighten it to avoid surprises in some way.

* jc/triangle-push-fixup:
  t/t5528-push-default: test pushdefault workflows
  t/t5528-push-default: generalize test_push_*
  push: change `simple` to accommodate triangular workflows
  config doc: rewrite push.default section
  t/t5528-push-default: remove redundant test_config lines
Merge branch 'jx/clean-interactive' (early part) into jch

* 'jx/clean-interactive' (early part):
  git-clean: refactor git-clean into two phases
  write_name{_quoted_relative,}(): remove redundant parameters
  quote_path_relative(): remove redundant parameter
  quote.c: substitute path_relative with relative_path
  path.c: refactor relative_path(), not only strip prefix
  test: add test cases for relative_path
Merge branch 'rr/rebase-checkout-reflog' into jch

Invocations of "git checkout" used internally by "git rebase" were
counted as "checkout", and affected later "git checkout -" to the
the user to an unexpected place.

The "bugfix" bits of the series is here.  The follow-up part to
reword reflog messages for steps in "rebase" are split to another
topic.

* rr/rebase-checkout-reflog:
  checkout: respect GIT_REFLOG_ACTION
  status: do not depend on rebase reflog messages
  t/t2021-checkout-last: "checkout -" should work after a rebase finishes
  wt-status: remove unused field in grab_1st_switch_cbdata
  t7512: test "detached from" as well