Enable adjusting frame sizes on MS-DOS

* src/dispnew.c (change_frame_size): Do not propagate changes to
child frames to root frames and vice versa.

* src/frame.c (adjust_frame_size): Do not change video modes
in resizing a child frame.

2 files changed, 15 insertions, 10 deletions

diff --git a/src/dispnew.c b/src/dispnew.c
index 180bc173f31..c252781b235 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -6618,13 +6618,14 @@ change_frame_size (struct frame *f, int new_width, int new_height,
 {
   Lisp_Object tail, frame;
 
-  if (FRAME_MSDOS_P (f))
+  if (FRAME_MSDOS_P (f) && !FRAME_PARENT_FRAME (f))
     {
       /* On MS-DOS, all frames use the same screen, so a change in
          size affects all frames.  Termcap now supports multiple
          ttys. */
       FOR_EACH_FRAME (tail, frame)
-        if (!FRAME_WINDOW_P (XFRAME (frame)))
+        if (!FRAME_WINDOW_P (XFRAME (frame))
+            && !FRAME_PARENT_FRAME (XFRAME (frame)))
           change_frame_size_1 (XFRAME (frame), new_width, new_height,
                                pretend, delay, safe);
     }
diff --git a/src/frame.c b/src/frame.c
index 250e7e53dd4..18e1078efe4 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -837,14 +837,18 @@ adjust_frame_size (struct frame *f, int new_text_width, int new_text_height,
   block_input ();
 
 #ifdef MSDOS
-  /* We only can set screen dimensions to certain values supported by
-     our video hardware.  Try to find the smallest size greater or
-     equal to the requested dimensions, while accounting for the fact
-     that the menu-bar lines are not counted in the frame height.  */
-  int dos_new_text_lines = new_text_lines + FRAME_TOP_MARGIN (f);
-
-  dos_set_window_size (&dos_new_text_lines, &new_text_cols);
-  new_text_lines = dos_new_text_lines - FRAME_TOP_MARGIN (f);
+  if (!FRAME_PARENT_FRAME (f))
+    {
+      /* We only can set screen dimensions to certain values supported
+         by our video hardware.  Try to find the smallest size greater
+         or equal to the requested dimensions, while accounting for the
+         fact that the menu-bar lines are not counted in the frame
+         height.  */
+      int dos_new_text_lines = new_text_lines + FRAME_TOP_MARGIN (f);
+
+      dos_set_window_size (&dos_new_text_lines, &new_text_cols);
+      new_text_lines = dos_new_text_lines - FRAME_TOP_MARGIN (f);
+    }
 #endif
 
   if (new_inner_width != old_inner_width)