There are currently two instances (fetch and push) where we want to
determine if submodules have changed given some revision specification.
These two instances don't use the same logic to generate a list of
changed submodules and as a result there is a fair amount of code
duplication.

This patch refactors these two code paths such that they both use the
same logic to generate a list of changed submodules.  This also makes it
easier for future callers to be able to reuse this logic as they only
need to create an argv_array with the revision specification to be using
during the revision walk.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Teach 'submodule_has_commits()' to ensure that if a commit exists in a
submodule, that it is also reachable from a ref.

This is a preparatory step prior to merging the logic which checks for
changed submodules when fetching or pushing.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Eliminate a call to 'xstrdup()' by changing the string_list
'changed_submodule_paths' to duplicated strings added to it.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The function 'add_oid_to_argv()' provides the same functionality as
'append_oid_to_argv()'.  Remove this duplicate function and instead use
'append_oid_to_argv()' where 'add_oid_to_argv()' was previously used.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Rename 'free_submodules_sha1s()' to 'free_submodules_oids()' since the
function frees a 'struct string_list' which has a 'struct oid_array'
stored in the 'util' field.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Rename 'add_sha1_to_array()' to 'append_oid_to_array()' to more
accurately describe what the function does, since it handles
'struct object_id' and not sha1 character arrays.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

The internals of the refs API around the cached refs has been
streamlined.

* mh/separate-ref-cache:
  do_for_each_entry_in_dir(): delete function
  files_pack_refs(): use reference iteration
  commit_packed_refs(): use reference iteration
  cache_ref_iterator_begin(): make function smarter
  get_loose_ref_cache(): new function
  get_loose_ref_dir(): function renamed from get_loose_refs()
  do_for_each_entry_in_dir(): eliminate `offset` argument
  refs: handle "refs/bisect/" in `loose_fill_ref_dir()`
  ref-cache: use a callback function to fill the cache
  refs: record the ref_store in ref_cache, not ref_dir
  ref-cache: introduce a new type, ref_cache
  refs: split `ref_cache` code into separate files
  ref-cache: rename `remove_entry()` to `remove_entry_from_dir()`
  ref-cache: rename `find_ref()` to `find_ref_entry()`
  ref-cache: rename `add_ref()` to `add_ref_entry()`
  refs_verify_refname_available(): use function in more places
  refs_verify_refname_available(): implement once for all backends
  refs_ref_iterator_begin(): new function
  refs_read_raw_ref(): new function
  get_ref_dir(): don't call read_loose_refs() for "refs/bisect"

Allow to lock a worktree immediately after it's created. This helps
prevent a race between "git worktree add; git worktree lock" and
"git worktree prune".

* nd/worktree-add-lock:
  worktree add: add --lock option

Many stale HTTP(s) links have been updated in our documentation.

* jk/update-links-in-docs:
  docs/bisect-lk2009: update java code conventions link
  docs/bisect-lk2009: update nist report link
  docs/archimport: quote sourcecontrol.net reference
  gitcore-tutorial: update broken link
  doc: replace or.cz gitwiki link with git.wiki.kernel.org
  doc: use https links to avoid http redirect

Plug a memleak.

* sf/putty-w-args:
  connect.c: fix leak in handle_ssh_variant

The completion script (in contrib/) learned to complete "git push
--delete b<TAB>" to complete branch name to be deleted.

* ab/completion-push-delete-ref:
  completion: expand "push --delete <remote> <ref>" for refs on that <remote>

The split-index code configuration code used an unsafe git_path()
function without copying its result out.

* cc/split-index-config:
  read-cache: avoid using git_path() in freshen_shared_index()

While handy, "git_path()" is a dangerous function to use as a
callsite that uses it safely one day can be broken by changes
to other code that calls it.  Reduction of its use continues.

* jk/war-on-git-path:
  am: drop "dir" parameter from am_state_init
  replace strbuf_addstr(git_path()) with git_path_buf()
  replace xstrdup(git_path(...)) with git_pathdup(...)
  use git_path_* helper functions
  branch: add edit_description() helper
  bisect: add git_path_bisect_terms helper

"git checkout" that handles a lot of paths has been optimized by
reducing the number of unnecessary checks of paths in the
has_dir_name() function.

* jh/add-index-entry-optim:
  read-cache: speed up has_dir_name (part 2)
  read-cache: speed up has_dir_name (part 1)
  read-cache: speed up add_index_entry during checkout
  p0006-read-tree-checkout: perf test to time read-tree
  read-cache: add strcmp_offset function

Doc update.

* ss/submodule-shallow-doc:
  gitmodules: clarify what history depth a shallow clone has

Doc update.

* ss/gitmodules-ignore-doc:
  gitmodules: clarify the ignore option values

The recently introduced conditional inclusion of configuration did
not work well when early-config mechanism was involved.

* nd/conditional-config-in-early-config:
  config: correct file reading order in read_early_config()
  config: handle conditional include when $GIT_DIR is not set up
  config: prepare to pass more info in git_config_with_options()

Doc update.

* ab/push-cas-doc-n-test:
  push: document & test --force-with-lease with multiple remotes

Travis CI learns to run coccicheck.

* ls/travis-coccicheck:
  travis-ci: add static analysis build job to run coccicheck

A recent update broke "git add -p ../foo" from a subdirectory.

* ps/pathspec-empty-prefix-origin:
  pathspec: honor `PATHSPEC_PREFIX_ORIGIN` with empty prefix

Having a git command on the upstream side of a pipe in a test
script will hide the exit status from the command, which may cause
us to fail to notice a breakage; rewrite tests in a script to avoid
this issue.

* pc/t2027-git-to-pipe-cleanup:
  t2027: avoid using pipes

"git rebase" learns "--signoff" option.

* gb/rebase-signoff:
  rebase: pass --[no-]signoff option to git am
  builtin/am: fold am_signoff() into am_append_signoff()
  builtin/am: honor --signoff also when --rebasing

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

gethostname(2) may not NUL terminate the buffer if hostname does
not fit; unfortunately there is no easy way to see if our buffer
was too small, but at least this will make sure we will not end up
using garbage past the end of the buffer.

* dt/xgethostname-nul-termination:
  xgethostname: handle long hostnames
  use HOST_NAME_MAX to size buffers for gethostname(2)

"ls-files --recurse-submodules" did not quite work well in a
project with nested submodules.

* jk/ls-files-recurse-submodules-fix:
  ls-files: fix path used when recursing into submodules
  ls-files: fix recurse-submodules with nested submodules

Various small fixes.

* rs/misc-cppcheck-fixes:
  server-info: avoid calling fclose(3) twice in update_info_file()
  files_for_each_reflog_ent_reverse(): close stream and free strbuf on error
  am: close stream on error, but not stdin

Hotfix for a topic that is already in 'master'.

* jk/snprintf-cleanups:
  replace: plug a memory leak

Doc cleanup.

* xy/format-patch-base:
  doc: trivial typo in git-format-patch.txt

Code cleanup.

* sb/checkout-recurse-submodules:
  submodule: remove a superfluous second check for the "new" variable

"git fetch-pack" was not prepared to accept ERR packet that the
upload-pack can send with a human-readable error message.  It
showed the packet contents with ERR prefix, so there was no data
loss, but it was redundant to say "ERR" in an error message.

* jt/fetch-pack-error-reporting:
  fetch-pack: show clearer error message upon ERR

Code cleanup.

* km/t1400-modernization:
  t1400: use consistent style for test_expect_success calls

Add finishing touches to a recent topic.

* jk/quarantine-received-objects:
  refs: reject ref updates while GIT_QUARANTINE_PATH is set
  receive-pack: document user-visible quarantine effects
  receive-pack: drop tmp_objdir_env from run_update_hook

Code cleanup.

* jk/loose-object-fsck:
  sha1_file: remove an used fd variable

"git submodule" script does not work well with strange pathnames.
Protect it from a path with slashes in them, at least.

* bw/submodule-with-bs-path:
  submodule: prevent backslash expantion in submodule names

The index file has a trailing SHA-1 checksum to detect file
corruption, and historically we checked it every time the index
file is used.  Omit the validation during normal use, and instead
verify only in "git fsck".

* jh/verify-index-checksum-only-in-fsck:
  read-cache: force_verify_index_checksum

In a 2- and 3-way merge of trees, more than one source trees often
end up sharing an identical subtree; optimize by not reading the
same tree multiple times in such a case.

* jh/unpack-trees-micro-optim:
  unpack-trees: avoid duplicate ODB lookups during checkout

The string-list API used a custom reallocation strategy that was
very inefficient, instead of using the usual ALLOC_GROW() macro,
which has been fixed.

* jh/string-list-micro-optim:
  string-list: use ALLOC_GROW macro when reallocing string_list

$GIT_DIR may in some cases be normalized with all symlinks resolved
while "gitdir" path expansion in the pattern does not receive the
same treatment, leading to incorrect mismatch.  This has been fixed.

* nd/conditional-config-include:
  config: resolve symlinks in conditional include's patterns
  path.c: and an option to call real_path() in expand_user_path()

Allow the http.postbuffer configuration variable to be set to a
size that can be expressed in size_t, which can be larger than
ulong on some platforms.

* dt/http-postbuffer-can-be-large:
  http.postbuffer: allow full range of ssize_t values