1 files changed, 29 insertions, 0 deletions

diff --git a/src/msdos.c b/src/msdos.c
index f466196f9af..f5dff6fb5bc 100644
--- a/src/msdos.c
+++ b/src/msdos.c
@@ -1196,6 +1196,10 @@ static Lisp_Object help_echo_window;
 static Lisp_Object help_echo_object;
 static int help_echo_pos;
 
+/* Non-zero means automatically select any window when the mouse
+   cursor moves into it.  */
+int x_autoselect_window_p;
+
 static int mouse_preempted = 0; /* non-zero when XMenu gobbles mouse events */
 
 /* Set the mouse pointer shape according to whether it is in the
@@ -3388,6 +3392,27 @@ dos_rawgetc ()
          might need to update mouse highlight.  */
       if (mouse_last_x != mouse_prev_x || mouse_last_y != mouse_prev_y)
         {
+          if (x_autoselect_window_p)
+            {
+              int mouse_area;
+              Lisp_Object mouse_window;
+
+              mouse_window = window_from_coordinates (SELECTED_FRAME(),
+                                                      mouse_last_x,
+                                                      mouse_last_y,
+                                                      &mouse_area, 0);
+              /* A window will be selected only when it is not
+                 selected now and last mouse movement event was not in
+                 it.  A minubuffer window will be selected iff it is
+                 active.  */
+              if (!EQ (mouse_window, selected_window)
+                  && (!MINI_WINDOW_P (XWINDOW (mouse_window))
+                      || (EQ (mouse_window, minibuf_window)
+                          && minibuf_level > 0)))
+                {
+                  Fselect_window (mouse_window);
+                }
+            }
           previous_help_echo = help_echo;
           help_echo = help_echo_object = help_echo_window = Qnil;
           help_echo_pos = -1;
@@ -5315,6 +5340,10 @@ syms_of_msdos ()
 
 This variable is used only by MSDOS terminals.  */);
   Vdos_unsupported_char_glyph = '\177';
+
+  DEFVAR_BOOL ("x-autoselect-window", &x_autoselect_window_p,
+    doc: /* *Non-nil means autoselect window with mouse pointer.  */);
+  x_autoselect_window_p = 0;
 #endif
 #ifndef subprocesses
   DEFVAR_BOOL ("delete-exited-processes", &delete_exited_processes,