Merge branch 'jc/clone-borrow' into jch

Allow "git clone --reference" to be used more safely.

* jc/clone-borrow:
  clone: --dissociate option to mark that reference is only temporary
Merge branch 'jc/checkout-local-track-report' into jch

The report from "git checkout" on a branch that builds on another
local branch by setting its branch.*.merge to branch name (not a
full refname) incorrectly said that the upstream is gone.

* jc/checkout-local-track-report:
  checkout: report upstream correctly even with loosely defined branch.*.merge
Merge branch 'jc/diff-b-m' into jch

Fix long-standing bug in "diff -B -M" output.

* jc/diff-b-m:
  diff -B -M: fix output for "copy and then rewrite" case
Merge branch 'jc/strbuf-add-lines-avoid-sp-ht-sequence' into jch

The commented output used to blindly add a SP before the payload
line, resulting in "# \t<indented text>\n" when the payload began
with a HT.  Instead, produce "#\t<indented text>\n".

* jc/strbuf-add-lines-avoid-sp-ht-sequence:
  strbuf_add_commented_lines(): avoid SP-HT sequence in commented lines
Merge branch 'jc/conflict-hint' into jch

Unlike all the other hints given in the commit log editor, the list
of conflicted paths were appended at the end without commented out.

* jc/conflict-hint:
  merge & sequencer: turn "Conflicts:" hint into a comment
  builtin/commit.c: extract ignore_non_trailer() helper function
  merge & sequencer: unify codepaths that write "Conflicts:" hint
  builtin/merge.c: drop a parameter that is never used
Merge branch 'jk/cache-tree-protect-from-broken-libgit2' into jch

* jk/cache-tree-protect-from-broken-libgit2:
  cache-tree: avoid infinite loop on zero-entry tree
Merge branch 'rs/use-child-process-init-more' into jch

* rs/use-child-process-init-more:
  bundle: split out ref writing from bundle_create
  bundle: split out a helper function to compute and write prerequisites
  bundle: split out a helper function to create pack data
  use child_process_init() to initialize struct child_process variables
Merge branch 'jk/fetch-reflog-df-conflict' into jch

Corner-case bugfixes for "git fetch" around reflog handling.

* jk/fetch-reflog-df-conflict:
  ignore stale directories when checking reflog existence
  fetch: load all default config at startup
Merge branch 'js/diff-highlight-avoid-sigpipe' into jch

* js/diff-highlight-avoid-sigpipe:
  diff-highlight: exit when a pipe is broken
Merge branch 'tm/line-log-first-parent' into jch

* tm/line-log-first-parent:
  line-log: fix crash when --first-parent is used
Merge branch 'nd/gitignore-trailing-whitespace' into jch

* nd/gitignore-trailing-whitespace:
  gitignore.txt: fix spelling of "backslash"
### match next
Merge branch 'nd/lockfile-absolute' into jch

The lockfile API can get confused which file to clean up when the
process moved the $cwd after creating a lockfile.

* nd/lockfile-absolute:
  lockfile.c: store absolute path
Merge branch 'jc/merge-bases' into jch

* jc/merge-bases:
  get_merge_bases(): always clean-up object flags
  bisect: clean flags after checking merge bases
Merge branch 'rs/ref-transaction-reflog' into jch

Reviews and comments?

* rs/ref-transaction-reflog:
  refs.c: allow deleting refs with a broken sha1
  refs.c: remove lock_any_ref_for_update
  refs.c: make unlock_ref/close_ref/commit_ref static
  refs.c: rename log_ref_setup to create_reflog
  reflog.c: use a reflog transaction when writing during expire
  refs.c: allow multiple reflog updates during a single transaction
  refs.c: only write reflog update if msg is non-NULL
  refs.c: add a flag to allow reflog updates to truncate the log
  refs.c: add a transaction function to append a reflog entry
  copy.c: make copy_fd preserve meaningful errno
  refs.c: add a function to append a reflog entry to a fd
  refs.c: add a new update_type field to ref_update
  refs.c: rename the transaction functions
  refs.c: make ref_transaction_delete a wrapper for ref_transaction_update
  refs.c make ref_transaction_create a wrapper to ref_transaction_update
Merge branch 'ms/submodule-update-config-doc' into jch

* ms/submodule-update-config-doc:
  submodule: clarify documentation for update subcommand