Fix fullscreen resizing of multiple frames on MS-Windows.

 src/w32term.h (struct w32_output): New members normal_width,
 normal_height, normal_top, normal_left, and prev_fsmode.
 (FRAME_NORMAL_WIDTH, FRAME_NORMAL_HEIGHT, FRAME_NORMAL_TOP)
 (FRAME_NORMAL_LEFT, FRAME_PREV_FSMODE): New macros to access these
 members of a frame.
 src/w32term.c (w32fullscreen_hook): Use FRAME_NORMAL_WIDTH,
 FRAME_NORMAL_HEIGHT, and FRAME_PREV_FSMODE, instead of static
 variables, to save and restore frame dimensions.  Use
 FRAME_NORMAL_LEFT and FRAME_NORMAL_TOP to restore frame position
 after returning from a 'fullscreen' configuration.  use
 SendMessage instead of PostMessage to send the SC_RESTORE message,
 to avoid races between the main thread and the input thread.

3 files changed, 50 insertions, 24 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index c60ff058e9d..62f210583ee 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,19 @@
 2013-03-23  Eli Zaretskii  <eliz@gnu.org>
 
+        * w32term.c (w32fullscreen_hook): Use FRAME_NORMAL_WIDTH,
+        FRAME_NORMAL_HEIGHT, and FRAME_PREV_FSMODE, instead of static
+        variables, to save and restore frame dimensions.  Use
+        FRAME_NORMAL_LEFT and FRAME_NORMAL_TOP to restore frame position
+        after returning from a 'fullscreen' configuration.  use
+        SendMessage instead of PostMessage to send the SC_RESTORE message,
+        to avoid races between the main thread and the input thread.
+
+        * w32term.h (struct w32_output): New members normal_width,
+        normal_height, normal_top, normal_left, and prev_fsmode.
+        (FRAME_NORMAL_WIDTH, FRAME_NORMAL_HEIGHT, FRAME_NORMAL_TOP)
+        (FRAME_NORMAL_LEFT, FRAME_PREV_FSMODE): New macros to access these
+        members of a frame.
+
         * w32term.c (w32fullscreen_hook): Record last value of the frame's
         'fullscreen' parameter.  Always record previous width and height
         of the frame, except when switching out of maximized modes, so
diff --git a/src/w32term.c b/src/w32term.c
index 3fe16b956bd..66d11164594 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -5660,9 +5660,6 @@ x_check_fullscreen (struct frame *f)
 static void
 w32fullscreen_hook (FRAME_PTR f)
 {
-  static int normal_width, normal_height;
-  static Lisp_Object prev_full;
-
   if (FRAME_VISIBLE_P (f))
     {
       int width, height, top_pos, left_pos, pixel_height, pixel_width;
@@ -5670,17 +5667,23 @@ w32fullscreen_hook (FRAME_PTR f)
       RECT workarea_rect;
 
       block_input ();
-      if (!(   EQ (prev_full, Qfullscreen)
-            || EQ (prev_full, Qfullboth)
-            || EQ (prev_full, Qmaximized)))
+      /* Record current "normal" dimensions for restoring later.  */
+      if (!(   FRAME_PREV_FSMODE (f) == FULLSCREEN_BOTH
+            || FRAME_PREV_FSMODE (f) == FULLSCREEN_MAXIMIZED))
         {
-          if (!EQ (prev_full, Qfullheight))
-            normal_height = cur_h;
-          if (!EQ (prev_full, Qfullwidth))
-            normal_width  = cur_w;
+          if (FRAME_PREV_FSMODE (f) != FULLSCREEN_HEIGHT)
+            {
+              FRAME_NORMAL_HEIGHT (f) = cur_h;
+              FRAME_NORMAL_TOP (f) = f->top_pos;
+            }
+          if (FRAME_PREV_FSMODE (f) != FULLSCREEN_WIDTH)
+            {
+              FRAME_NORMAL_WIDTH (f)  = cur_w;
+              FRAME_NORMAL_LEFT (f) = f->left_pos;
+            }
         }
-      eassert (normal_height > 0);
-      eassert (normal_width > 0);
+      eassert (FRAME_NORMAL_HEIGHT (f) > 0);
+      eassert (FRAME_NORMAL_WIDTH (f) > 0);
       x_real_positions (f, &f->left_pos, &f->top_pos);
       x_fullscreen_adjust (f, &width, &height, &top_pos, &left_pos);
 
@@ -5693,16 +5696,15 @@ w32fullscreen_hook (FRAME_PTR f)
          mouse pointer hovers over the window edges, becaise the WM
          will still think the window is maximized.  */
       if (f->want_fullscreen != FULLSCREEN_BOTH)
-        PostMessage (FRAME_W32_WINDOW (f), WM_SYSCOMMAND, SC_RESTORE, 0);
+        SendMessage (FRAME_W32_WINDOW (f), WM_SYSCOMMAND, SC_RESTORE, 0);
 
+      FRAME_PREV_FSMODE (f) = f->want_fullscreen;
       switch (f->want_fullscreen)
         {
         case FULLSCREEN_BOTH:
-          prev_full = Qfullboth;
           PostMessage (FRAME_W32_WINDOW (f), WM_SYSCOMMAND, SC_MAXIMIZE, 0);
           break;
         case FULLSCREEN_MAXIMIZED:
-          prev_full = Qmaximized;
           height =
             FRAME_PIXEL_HEIGHT_TO_TEXT_LINES (f, pixel_height)
             - XINT (Ftool_bar_lines_needed (selected_frame))
@@ -5714,28 +5716,25 @@ w32fullscreen_hook (FRAME_PTR f)
           top_pos = workarea_rect.top;
           break;
         case FULLSCREEN_WIDTH:
-          prev_full = Qfullwidth;
           width  =
             FRAME_PIXEL_WIDTH_TO_TEXT_COLS (f, pixel_width)
             - FRAME_SCROLL_BAR_COLS (f);
-          height = normal_height;
+          height = FRAME_NORMAL_HEIGHT (f);
           left_pos = workarea_rect.left;
           break;
         case FULLSCREEN_HEIGHT:
-          prev_full = Qfullheight;
           height =
             FRAME_PIXEL_HEIGHT_TO_TEXT_LINES (f, pixel_height)
             - XINT (Ftool_bar_lines_needed (selected_frame))
             + (NILP (Vmenu_bar_mode) ? 1 : 0);
-          width = normal_width;
+          width = FRAME_NORMAL_WIDTH (f);
           top_pos = workarea_rect.top;
           break;
         case FULLSCREEN_NONE:
-          prev_full = Qnil;
-          height = normal_height;
-          width = normal_width;
-          /* FIXME: Should restore the original position of the frame.  */
-          top_pos = left_pos = 0;
+          height = FRAME_NORMAL_HEIGHT (f);
+          width = FRAME_NORMAL_WIDTH (f);
+          left_pos = FRAME_NORMAL_LEFT (f);
+          top_pos = FRAME_NORMAL_TOP (f);
           break;
         }
 
diff --git a/src/w32term.h b/src/w32term.h
index a31c5de193d..b319f0ca592 100644
--- a/src/w32term.h
+++ b/src/w32term.h
@@ -359,6 +359,12 @@ struct w32_output
   /* The background for which the above relief GCs were set up.
      They are changed only when a different background is involved.  */
   unsigned long relief_background;
+
+  /* Frame geometry and full-screen mode before it was resized by
+     specifying the 'fullscreen' frame parameter.  Used to restore the
+     geometry when 'fullscreen' is reset to nil.  */
+  int normal_width, normal_height, normal_top, normal_left;
+  int prev_fsmode;
 };
 
 extern struct w32_output w32term_display;
@@ -390,6 +396,13 @@ extern struct w32_output w32term_display;
 
 #define FRAME_SMALLEST_FONT_HEIGHT(F) \
      FRAME_W32_DISPLAY_INFO(F)->smallest_font_height
+
+#define FRAME_NORMAL_WIDTH(F)  ((F)->output_data.w32->normal_width)
+#define FRAME_NORMAL_HEIGHT(F) ((F)->output_data.w32->normal_height)
+#define FRAME_NORMAL_TOP(F)    ((F)->output_data.w32->normal_top)
+#define FRAME_NORMAL_LEFT(F)   ((F)->output_data.w32->normal_left)
+#define FRAME_PREV_FSMODE(F)   ((F)->output_data.w32->prev_fsmode)
+
 
 /* W32-specific scroll bar stuff.  */