Merge branch 'master' into next

Merge branch 'master' into next

* master: (32 commits)
  t/t3415: use && where applicable.
  SubmittingPatches: Document some extra tags used in commit messages
  diffcore-pickaxe.c: a void function shouldn't try to return something
  Make test script t9157 executable
  Martin Langhoff has a new e-mail address
  Documentation/git-clone: describe --mirror more verbosely
  do not depend on signed integer overflow
  work around buggy S_ISxxx(m) implementations
  xdiff: cast arguments for ctype functions to unsigned char
  init: plug tiny one-time memory leak
  diffcore-pickaxe.c: remove unnecessary curly braces
  t3020 (ls-files-error-unmatch): remove stray '1' from end of file
  setup: make sure git dir path is in a permanent buffer
  environment.c: remove unused variable
  Add MinGW-specific execv() override.
  Fix Windows-specific macro redefinition warning.
  Fix 'clone' failure at DOS root directory.
  mingw: do not crash on open(NULL, ...)
  git-am: fix detection of absolute paths for windows
  Side-step MSYS-specific path "corruption" leading to t5560 failure.
  ...