Sync with 2.15.4

* maint-2.15: (29 commits)
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  t6130/t9350: prepare for stringent Win32 path validation
  quote-stress-test: allow skipping some trials
  quote-stress-test: accept arguments to test via the command-line
  tests: add a helper to stress test argument quoting
  mingw: fix quoting of arguments
  Disallow dubiously-nested submodule git directories
  protect_ntfs: turn on NTFS protection by default
  path: also guard `.gitmodules` against NTFS Alternate Data Streams
  is_ntfs_dotgit(): speed it up
  mingw: disallow backslash characters in tree objects' file names
  path: safeguard `.git` against NTFS Alternate Streams Accesses
  clone --recurse-submodules: prevent name squatting on Windows
  is_ntfs_dotgit(): only verify the leading segment
  ...

diff --cc builtin/clone.c
Simple merge

diff --cc builtin/submodule--helper.c
index 13312ac808ce2dd6562a57d350ff1cb6339f7955,0d03fa8bf9ce49495b6bad0ed27ffb8b23587980..3c4b3b7032fa2053646d0a6a271e83fa614dd313
--- 1/builtin/submodule--helper.c
--- 2/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@@ -13,17 -13,8 +13,18 @@@
  #include "remote.h"
  #include "refs.h"
  #include "connect.h"
 +#include "revision.h"
 +#include "diffcore.h"
 +#include "diff.h"
+ #include "dir.h"
  
 +#define OPT_QUIET (1 << 0)
 +#define OPT_CACHED (1 << 1)
 +#define OPT_RECURSIVE (1 << 2)
 +
 +typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
 +                                void *cb_data);
 +
  static char *get_default_remote(void)
  {
        char *dest = NULL, *ret;

diff --cc config.mak.uname
Simple merge

diff --cc connect.c
Simple merge

diff --cc environment.c
index 63ac38a46f8f01ee3d09ed8e09bd93acba63b21a,bca118772bb391a4ab957ef58deddacab197e7c4..31a39e4a43b7ee8fc3867f6956f1f71707295594
--- 1/environment.c
--- 2/environment.c
+++ b/environment.c
@@@ -73,10 -73,9 +73,10 @@@ enum log_refs_config log_all_ref_update
  int protect_hfs = PROTECT_HFS_DEFAULT;
  
  #ifndef PROTECT_NTFS_DEFAULT
- #define PROTECT_NTFS_DEFAULT 0
+ #define PROTECT_NTFS_DEFAULT 1
  #endif
  int protect_ntfs = PROTECT_NTFS_DEFAULT;
 +const char *core_fsmonitor;
  
  /*
   * The character that begins a commented line in user-editable file

diff --cc fast-import.c
Simple merge

diff --cc git-compat-util.h
Simple merge

diff --cc git-submodule.sh
Simple merge

diff --cc read-cache.c
Simple merge

diff --cc submodule-config.c
Simple merge

diff --cc submodule.c
Simple merge

diff --cc submodule.h
Simple merge

diff --cc t/t9300-fast-import.sh
Simple merge

diff --cc transport-helper.c
Simple merge

diff --cc tree-walk.c
Simple merge

diff --cc unpack-trees.c
Simple merge