Merge branch 'mk/mingw-winansi-ttyname-termination-fix'

A potential but unlikely buffer overflow in Windows port has been
fixed.

* mk/mingw-winansi-ttyname-termination-fix:
mingw: consider that UNICODE_STRING::Length counts bytes

diff --combined compat/winansi.c
index cb725fb02f6e4f48c4f314c3c6c5e8535aa6eda8,6b4f736fdcc16d979ad3e8047a34e98afc33ddda..97d84a96ededd9446ad409db2a410f9a03879e9b
--- 1/compat/winansi.c
--- 2/compat/winansi.c
+++ b/compat/winansi.c
@@@ -7,9 -7,6 +7,9 @@@
  #include <wingdi.h>
  #include <winreg.h>
  
 +/* In this file, we actually want to use Windows' own isatty(). */
 +#undef isatty
 +
  /*
   ANSI codes used by git: m, K
  
@@@ -495,7 -492,7 +495,7 @@@ static inline ioinfo* _pioinfo(int fd
                        (fd & (IOINFO_ARRAY_ELTS - 1)) * sizeof_ioinfo);
  }
  
 -static int init_sizeof_ioinfo()
 +static int init_sizeof_ioinfo(void)
  {
        int istty, wastty;
        /* don't init twice */
@@@ -556,7 -553,7 +556,7 @@@ static void detect_msys_tty(int fd
                        buffer, sizeof(buffer) - 2, &result)))
                return;
        name = nameinfo->Name.Buffer;
-       name[nameinfo->Name.Length] = 0;
+       name[nameinfo->Name.Length / sizeof(*name)] = 0;
  
        /* check if this could be a MSYS2 pty pipe ('msys-XXXX-ptyN-XX') */
        if (!wcsstr(name, L"msys-") || !wcsstr(name, L"-pty"))
@@@ -573,36 -570,6 +573,36 @@@
  
  #endif
  
 +int winansi_isatty(int fd)
 +{
 +      int res = isatty(fd);
 +
 +      if (res) {
 +              /*
 +               * Make sure that /dev/null is not fooling Git into believing
 +               * that we are connected to a terminal, as "_isatty() returns a
 +               * nonzero value if the descriptor is associated with a
 +               * character device."; for more information, see
 +               *
 +               * https://msdn.microsoft.com/en-us/library/f4s0ddew.aspx
 +               */
 +              HANDLE handle = (HANDLE)_get_osfhandle(fd);
 +              if (fd == STDIN_FILENO) {
 +                      DWORD dummy;
 +
 +                      if (!GetConsoleMode(handle, &dummy))
 +                              res = 0;
 +              } else if (fd == STDOUT_FILENO || fd == STDERR_FILENO) {
 +                      CONSOLE_SCREEN_BUFFER_INFO dummy;
 +
 +                      if (!GetConsoleScreenBufferInfo(handle, &dummy))
 +                              res = 0;
 +              }
 +      }
 +
 +      return res;
 +}
 +
  void winansi_init(void)
  {
        int con1, con2;