Merge branch 'master' into next
* master:
Fix missing 'does' in man-page for 'git checkout'
dir.c: squelch false uninitialized memory warning
git-send-email.perl: ensure $domain is defined before using it
wt-status.c: don't leak directory entries when processing untracked,ignored
t6050 (replace): fix bogus "fetch branch with replacement" test
Documentation: Refer to git-commit-tree in git-filter-branch help
update comment and documentation for :/foo syntax
Improvements to `git checkout -h`
contrib/completion: --no-index option to git diff
prefer test -h over test -L in shell scripts
CodingGuidelines: spell Arithmetic Expansion with $(($var))
t1503: Fix arithmetic expansion syntax error when using dash
strbuf.h: fix comment typo