Merge branch 'so/rebase-doc' into maint

* so/rebase-doc:
  Documentation/git-rebase.txt: <upstream> must be given to specify <branch>
  Documentation/git-rebase.txt: -f forces a rebase that would otherwise be a no-op
Merge branch 'jk/send-pack-many-refspecs' into maint

"git push" over HTTP transport had an artificial limit on number of
refs that can be pushed imposed by the command line length.

* jk/send-pack-many-refspecs:
  send-pack: take refspecs over stdin
Merge branch 'jk/index-pack-threading-races' into maint

When receiving an invalid pack stream that records the same object
twice, multiple threads got confused due to a race.

* jk/index-pack-threading-races:
  index-pack: fix race condition with duplicate bases
Merge branch 'mb/fast-import-delete-root' into maint

An attempt to remove the entire tree in the "git fast-import" input
stream caused it to misbehave.

* mb/fast-import-delete-root:
  fast-import: fix segfault in store_tree()
  t9300: test filedelete command
Merge branch 'mk/reachable-protect-detached-head' into maint

Reachability check (used in "git prune" and friends) did not add a
detached HEAD as a starting point to traverse objects still in use.

* mk/reachable-protect-detached-head:
  reachable.c: add HEAD to reachability starting commits
Merge branch 'ta/config-add-to-empty-or-true-fix' into maint

"git config --add section.var val" used to lose existing
section.var whose value was an empty string.

* ta/config-add-to-empty-or-true-fix:
  config: avoid a funny sentinel value "a^"
  make config --add behave correctly for empty and NULL values
Merge branch 'jk/fsck-exit-code-fix' into maint

"git fsck" failed to report that it found corrupt objects via its
exit status in some cases.

* jk/fsck-exit-code-fix:
  fsck: return non-zero status on missing ref tips
  fsck: exit with non-zero status upon error from fsck_obj()
Git 2.1.2

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'pr/use-default-sigpipe-setting'

We used to get confused when a process called us with SIGPIPE
ignored; we do want to die with SIGPIPE when the output is not
read by default, and do ignore the signal when appropriate.

* pr/use-default-sigpipe-setting:
  mingw.h: add dummy functions for sigset_t operations
  unblock and unignore SIGPIPE
Merge branch 'sb/merge-recursive-copy-paste-fix'

"git merge-recursive" had a small bug that could have made it
mishandle "one side deleted, the other side did not touch it" in a
rare corner case, where the other side actually did touch to cause
the blob object names to be different but both blobs before and
after the change normalize to the same (e.g. correcting mistake to
check in a blob with CRLF line endings by replacing it with another
blob that records the same contents with LF line endings).

* sb/merge-recursive-copy-paste-fix:
  merge-recursive: remove stale commented debugging code
  merge-recursive: fix copy-paste mistake
Merge branch 'jc/test-lazy-prereq'

Test-script clean-up.

* jc/test-lazy-prereq:
  tests: drop GIT_*_TIMING_TESTS environment variable support
Merge branch 'jt/itimer-autoconf'

setitmer(2) and related API elements can be configured from
Makefile but autoconf did not know about it.

* jt/itimer-autoconf:
  autoconf: check for setitimer()
  autoconf: check for struct itimerval
  git-compat-util.h: add missing semicolon after struct itimerval
Sync with 2.1.2

* maint:
  Git 2.1.2
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
### match next
Merge branch 'sp/stream-clean-filter' into jch

* 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
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:
  SQUASH???
  check-headers: add header usage checks for .c files
  Makefile: add check-headers target
  cleanups: ensure that git-compat-util.h is included first