MDEV-4330 - get_tty_password() does not work if input redirection is used.

  
The reason is the limitation of ReadConsole() API, it returns error if handle to redirected  input  is used.
  
 The fix is to use a  handle returned by CreateFile("CONIN$",...), rather than GetStdHandle(STD_HANDLE_INPUT) to get the true console handle.

libmysql/get_password.c

@@ -67,8 +67,8 @@ void get_tty_password_buff(const char *opt_message, char *to, size_t length)
   char *pos=to,*end=to+length-1;
   int i=0;
 
-  consoleinput= GetStdHandle(STD_INPUT_HANDLE);
-  if (!consoleinput) 
+  consoleinput= CreateFile("CONIN$", GENERIC_WRITE | GENERIC_READ, 0 , NULL, 0, 0, NULL); 
+  if (consoleinput == NULL || consoleinput == INVALID_HANDLE_VALUE) 
   {
      /* This is a GUI application or service  without console input, bail out. */
      *to= 0;
@@ -108,6 +108,7 @@ void get_tty_password_buff(const char *opt_message, char *to, size_t length)
   }
   /* Reset console mode after password input. */ 
   SetConsoleMode(consoleinput, oldstate);
+  CloseHandle(consoleinput);
   *pos=0;
   _cputs("\n");
 }