[h-e-w] Patch to fix frame positioning with negative top/left values on Windows

[Francis Litterio]

Emacs developers,

This patch to the CVS Emacs sources fixes the way that function
x_calc_absolute_position() accounts for the Windows-drawn borders around
a frame when converting a negative 'top or 'left parameter into the
equivalent positive value.

I have submitted this patch before, but RMS told me that the FSF needed
a copyright assignment from me before it could applied.  The FSF now has
mysigned the copyright assignment, so please let me know if there's any
problem with this patch.  I've been running Emacs with it for some
months with no problems.
--
Francis Litterio
franl <at> world . std . com


diff -w -u -u -w -r1.228 w32term.c
--- w32term.c   4 Jul 2005 16:06:37 -0000       1.228
+++ w32term.c   7 Jul 2005 16:19:39 -0000
@@ -5438,17 +5438,58 @@
 {
   int flags = f->size_hint_flags;
 
-  /* Treat negative positions as relative to the leftmost bottommost
+  /* left_right_borders_width holds the sum of the widths of the frame's left
+     and right borders (in pixels) drawn by Windows. */
+
+  unsigned int left_right_borders_width = 8;   /* A sensible default value. */
+
+  /* top_bottom_borders_height holds the sum of the heights of the frame's top 
and
+     bottom borders (in pixels) drawn by Windows. */
+
+  unsigned int top_bottom_borders_height = 32;  /* A sensible default value. */
+
+  /* Now obtain the actual values of the above two variables.  If we fail to
+     obtain the actual values, we will use the defaults assigned above.  We 
compute
+     the border width (height) by subtracting the width (height) of the frame's
+     client area from the width (height) of the frame's entire window.
+  */
+
+  WINDOWPLACEMENT wp = { 0 };
+
+  BOOL status = GetWindowPlacement (FRAME_W32_WINDOW (f), &wp);
+
+  if (status != FALSE)
+  {
+      RECT client_rect = { 0 };
+
+      status = GetClientRect (FRAME_W32_WINDOW (f), &client_rect);
+
+      if (status != FALSE)
+      {
+         left_right_borders_width =
+             (wp.rcNormalPosition.right - wp.rcNormalPosition.left) -
+             (client_rect.right - client_rect.left);
+
+         top_bottom_borders_height =
+             (wp.rcNormalPosition.bottom - wp.rcNormalPosition.top) -
+             (client_rect.bottom - client_rect.top);
+      }
+  }
+
+  /* Treat negative positions as relative to the rightmost bottommost
      position that fits on the screen.  */
   if (flags & XNegative)
     f->left_pos = (FRAME_W32_DISPLAY_INFO (f)->width
                   - FRAME_PIXEL_WIDTH (f)
-                  + f->left_pos);
+                  + f->left_pos
+                  - (left_right_borders_width - 1));
 
   if (flags & YNegative)
     f->top_pos = (FRAME_W32_DISPLAY_INFO (f)->height
                  - FRAME_PIXEL_HEIGHT (f)
-                 + f->top_pos);
+                 + f->top_pos
+                  - (top_bottom_borders_height - 1));
+
   /* The left_pos and top_pos
      are now relative to the top and left screen edges,
      so the flags should correspond.  */