D7: editor multi-cursor support

Add secondary_cursors field to Editor with insert_char_multi,
delete_back_multi, delete_forward_multi methods. Right-to-left
processing ensures position shifts don't corrupt earlier insertions.

7 new tests: add/clear, all_positions, insert, delete_back,
delete_forward, unicode, duplicate-add.

local/recipes/tools/diffutils/source/gnulib-tests/ioctl.c

@@ -0,0 +1,92 @@
+/* ioctl.c --- wrappers for Windows ioctl function
+
+   Copyright (C) 2008-2017 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Paolo Bonzini */
+
+#include <config.h>
+
+#include <sys/ioctl.h>
+
+#include <stdarg.h>
+
+#if HAVE_IOCTL
+
+/* Provide a wrapper with the POSIX prototype.  */
+# undef ioctl
+int
+rpl_ioctl (int fd, int request, ... /* {void *,char *} arg */)
+{
+  void *buf;
+  va_list args;
+
+  va_start (args, request);
+  buf = va_arg (args, void *);
+  va_end (args);
+
+  /* Cast 'request' so that when the system's ioctl function takes a 64-bit
+     request argument, the value gets zero-extended, not sign-extended.  */
+  return ioctl (fd, (unsigned int) request, buf);
+}
+
+#else /* mingw */
+
+# include <errno.h>
+
+/* Get HANDLE.  */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+
+# include "fd-hook.h"
+/* Get _get_osfhandle.  */
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
+
+static int
+primary_ioctl (int fd, int request, void *arg)
+{
+  /* We don't support FIONBIO on pipes here.  If you want to make pipe
+     fds non-blocking, use the gnulib 'nonblocking' module, until
+     gnulib implements fcntl F_GETFL / F_SETFL with O_NONBLOCK.  */
+
+  if ((HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE)
+    errno = ENOSYS;
+  else
+    errno = EBADF;
+  return -1;
+}
+
+int
+ioctl (int fd, int request, ... /* {void *,char *} arg */)
+{
+  void *arg;
+  va_list args;
+
+  va_start (args, request);
+  arg = va_arg (args, void *);
+  va_end (args);
+
+# if WINDOWS_SOCKETS
+  return execute_all_ioctl_hooks (primary_ioctl, fd, request, arg);
+# else
+  return primary_ioctl (fd, request, arg);
+# endif
+}
+
+#endif