Merge branch 'jc/push-cert' into jch

Allow "git push" request to be signed, so that it can be verified and
audited, using the GPG signature of the person who pushed, that the
tips of branches at a public repository really point the commits
the pusher wanted to, without having to "trust" the server.

* jc/push-cert: (24 commits)
  receive-pack::hmac_sha1(): copy the entire SHA-1 hash out
  signed push: allow stale nonce in stateless mode
  signed push: teach smart-HTTP to pass "git push --signed" around
  signed push: fortify against replay attacks
  signed push: add "pushee" header to push certificate
  signed push: remove duplicated protocol info
  send-pack: send feature request on push-cert packet
  receive-pack: GPG-validate push certificates
  push: the beginning of "git push --signed"
  pack-protocol doc: typofix for PKT-LINE
  gpg-interface: move parse_signature() to where it should be
  gpg-interface: move parse_gpg_output() to where it should be
  send-pack: clarify that cmds_sent is a boolean
  send-pack: refactor inspecting and resetting status and sending commands
  send-pack: rename "new_refs" to "need_pack_data"
  receive-pack: factor out capability string generation
  send-pack: factor out capability string generation
  send-pack: always send capabilities
  send-pack: refactor decision to send update per ref
  send-pack: move REF_STATUS_REJECT_NODELETE logic a bit higher
  ...
Merge branch 'nd/archive-pathspec' into jch

"git archive" learned to filter what gets archived with pathspec.

* nd/archive-pathspec:
  archive: support filtering paths with glob
Merge branch 'bw/use-write-script-in-tests' into jch

* bw/use-write-script-in-tests:
  t/lib-credential: use write_script
Merge branch 'sp/stream-clean-filter' into jch

When running a required clean filter, we do not have to mmap the
original before feeding the filter.  Instead, stream the file
contents directly to the filter and process its output.

* sp/stream-clean-filter:
  sha1_file: don't convert off_t to size_t too early to avoid potential die()
  convert: stream from fd to required clean filter to reduce used address space
  copy_fd(): do not close the input file descriptor
  mmap_limit: introduce GIT_MMAP_LIMIT to allow testing expected mmap size
  memory_limit: use git_env_ulong() to parse GIT_ALLOC_LIMIT
  config.c: add git_env_ulong() to parse environment variable
  convert: drop arguments other than 'path' from would_convert_to_git()

# Conflicts:
# 	wrapper.c
### match next
Merge branch 'tr/remerge-diff' into jch

"log -p" output learns a new way to let users inspect a merge
commit by showing the differences between the automerged result
with conflicts the person who recorded the merge would have seen
and the final conflict resolution that was recorded in the merge.

* tr/remerge-diff:
  log --remerge-diff: show what the conflict resolution changed
  name-hash: allow dir hashing even when !ignore_case
  merge-recursive: allow storing conflict hunks in index
  merge_diff_mode: fold all merge diff variants into an enum
  combine-diff: do not pass revs->dense_combined_merges redundantly
  merge-recursive: -Xindex-only to leave worktree unchanged
  merge-recursive: internal flag to avoid touching the worktree
  merge-recursive: remove dead conditional in update_stages()

# Conflicts:
# 	merge-recursive.c
Merge branch 'da/include-compat-util-first-in-c' into jch

So... what is happening to this topic?  I think the bottom one is a
reasonable clean-up without too much churn, but I am not sure about
the rest.

* da/include-compat-util-first-in-c:
  cleanups: ensure that git-compat-util.h is included first
Merge branch 'so/rebase-doc-fork-point' into jch

* so/rebase-doc-fork-point:
  Documentation/git-rebase.txt: document when --fork-point is auto-enabled
Merge branch 'sk/tag-contains-wo-recursion' into jch

* sk/tag-contains-wo-recursion:
  t7004: give the test a bit more stack space
Merge branch 'jc/push-cert-hmac-optim' into jch

This is "we could do this if we wanted to", not "we measured and it
improves performance critical codepath".

* jc/push-cert-hmac-optim:
  receive-pack: truncate hmac early and convert only necessary bytes
  sha1_to_hex: split out "hex-format n bytes" helper and use it
Merge branch 'dt/cache-tree-repair' into jch

This fixes a topic that has graduated to 'master'.

* dt/cache-tree-repair:
  t0090: avoid passing empty string to printf %d
Merge branch 'rs/sha1-array-test' into jch

* rs/sha1-array-test:
  sha1-lookup: handle duplicates in sha1_pos()
  sha1-array: add test-sha1-array and basic tests
Merge branch 'rs/daemon-fixes' into jch

"git daemon" (with NO_IPV6 build configuration) used to incorrectly
use the hostname even when gethostbyname() reported that the given
hostname is not found.

* rs/daemon-fixes:
  daemon: remove write-only variable maxfd
  daemon: fix error message after bind()
  daemon: handle gethostbyname() error
Merge branch 'mh/lockfile' into jch

The lockfile API and its users have been cleaned up.

* mh/lockfile: (38 commits)
  lockfile.h: extract new header file for the functions in lockfile.c
  hold_locked_index(): move from lockfile.c to read-cache.c
  hold_lock_file_for_append(): restore errno before returning
  get_locked_file_path(): new function
  lockfile.c: rename static functions
  lockfile: rename LOCK_NODEREF to LOCK_NO_DEREF
  commit_lock_file_to(): refactor a helper out of commit_lock_file()
  trim_last_path_component(): replace last_path_elm()
  resolve_symlink(): take a strbuf parameter
  resolve_symlink(): use a strbuf for internal scratch space
  lockfile: change lock_file::filename into a strbuf
  commit_lock_file(): use a strbuf to manage temporary space
  try_merge_strategy(): use a statically-allocated lock_file object
  try_merge_strategy(): remove redundant lock_file allocation
  struct lock_file: declare some fields volatile
  lockfile: avoid transitory invalid states
  git_config_set_multivar_in_file(): avoid call to rollback_lock_file()
  dump_marks(): remove a redundant call to rollback_lock_file()
  api-lockfile: document edge cases
  commit_lock_file(): rollback lock file on failure to rename
  ...

# Conflicts:
# 	lockfile.c
# 	merge-recursive.c
Merge branch 'mh/lockfile-stdio' into jch

* mh/lockfile-stdio:
  commit_packed_refs(): reimplement using fdopen_lock_file()
  dump_marks(): reimplement using fdopen_lock_file()
  fdopen_lock_file(): access a lockfile using stdio