Merge branch 'nl/rebase-i-cheat-sheet'

* nl/rebase-i-cheat-sheet:
  rebase -i: remind that the lines are top-to-bottom
Merge branch 'rs/unpack-trees-leakfix'

By René Scharfe
* rs/unpack-trees-leakfix:
  unpack-trees: plug minor memory leak
  unpack-trees: don't perform any index operation if we're not merging
Merge branch 'jc/maint-clean-nested-worktree-in-subdir'

"git clean -d -f" (not "-d -f -f") is supposed to protect nested working
trees of independent git repositories that exist in the current project
working tree from getting removed, but the protection applied only to such
working trees that are at the top-level of the current project by mistake.

* jc/maint-clean-nested-worktree-in-subdir:
  clean: preserve nested git worktree in subdirectories
Merge branch 'jk/diff-no-rename-empty'

Forbids rename detection logic from matching two empty files as renames
during merge-recursive to prevent mismerges.

By Jeff King
* jk/diff-no-rename-empty:
  merge-recursive: don't detect renames of empty files
  teach diffcore-rename to optionally ignore empty content
  make is_empty_blob_sha1 available everywhere
  drop casts from users EMPTY_TREE_SHA1_BIN
Merge branch 'rs/combine-diff-zero-context-at-the-beginning'

Fixes an age old corner case bug in combine diff (only triggered with -U0
and the hunk at the beginning of the file needs to be shown).

By René Scharfe
* rs/combine-diff-zero-context-at-the-beginning:
  combine-diff: fix loop index underflow
Merge branch 'jk/branch-quiet'

Even with "-q"uiet option, "checkout" used to report setting up tracking.
Also "branch" learns "-q"uiet option to squelch informational message.

By Jeff King
* jk/branch-quiet:
  teach "git branch" a --quiet option
  checkout: suppress tracking message with "-q"
Merge branch 'sl/autoconf'

Updates our configure.ac to follow a better "autoconf" style.

By Stefano Lattarini
* sl/autoconf:
  configure: be more idiomatic
  configure: avoid some code repetitions thanks to m4_{push,pop}def
  configure: move definitions of private m4 macros before AC_INIT invocation
Merge branch 'jk/http-backend-keep-committer-ident-env'

The smart-http backend used to always override GIT_COMMITTER_* variables
with REMOTE_USER and REMOTE_ADDR.

By Jeff King
* jk/http-backend-keep-committer-ident-env:
  http-backend: respect existing GIT_COMMITTER_* variables
Merge branch 'wk/gitweb-snapshot-use-if-modified-since'

Makes 'snapshot' request to "gitweb" honor If-Modified-Since: header,
based on the commit date.

By W. Trevor King
* wk/gitweb-snapshot-use-if-modified-since:
  gitweb: add If-Modified-Since handling to git_snapshot().
  gitweb: refactor If-Modified-Since handling
  gitweb: add `status` headers to git_feed() responses.
Merge branch 'bw/spawn-via-shell-path'

"sh" on the user's PATH may be utterly broken on some systems;
consistently use SHELL_PATH even from inside run-command API.

By Ben Walton
* bw/spawn-via-shell-path:
  Use SHELL_PATH from build system in run_command.c:prepare_shell_cmd
Merge branch 'jc/commit-unedited-template'

When "git commit --template F" errors out because the user did not touch
the message, it claimed that it aborts due to "empty message", which was
utterly wrong.

By Junio C Hamano (4) and Adam Monsen (1)
* jc/commit-unedited-template:
  Documentation/git-commit: rephrase the "initial-ness" of templates
  git-commit.txt: clarify -t requires editing message
  commit: rephrase the error when user did not touch templated log message
  commit: do not trigger bogus "has templated message edited" check
  t7501: test the right kind of breakage
Merge branch 'jk/add-p-skip-conflicts'

Excludes conflicted paths from "add -p" processing, as it is not prepared
to handle them.

By Jeff King
* jk/add-p-skip-conflicts:
  add--interactive: ignore unmerged entries in patch mode
RelNotes: the second batch of topics graduated to 'master'

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'master' into next

* master:
  RelNotes: the second batch of topics graduated to 'master'
mergesort: rename it to llist_mergesort()

Even though the function is generic enough, <anything>sort() inherits
connotations from the standard function qsort() that sorts an array.
Rename it to llist_mergesort() and describe the external interface in
its header file.

This incidentally avoids name clashes with mergesort() some platforms
declare in, and contaminate user namespace with, their <stdlib.h>.

Reported-by: Brian Gernhardt
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'rs/commit-list-sort-in-batch' into next

* rs/commit-list-sort-in-batch:
  mergesort: rename it to llist_mergesort()