File confine_to_shape.diff of Package xorg-x11-server

Index: dix/events.c
================================================================================
--- dix/events.c
+++ dix/events.c
@@ -661,37 +661,80 @@
 {
     BoxRec box;
     int x = *px, y = *py;
-    int incx = 1, incy = 1;
     SpritePtr pSprite;
+    int         nbox;
+    BoxPtr      pbox;
+    int                d, min = (~0U >> 1), dx2, dy2, x_r, y_r;
 
     pSprite = pDev->spriteInfo->sprite;
     if (RegionContainsPoint(shape, x, y, &box))
 	return;
-    box = *RegionExtents(shape);
-    /* this is rather crude */
-    do {
-	x += incx;
-	if (x >= box.x2)
-	{
-	    incx = -1;
-	    x = *px - 1;
+
+    for (nbox = REGION_NUM_RECTS (shape),
+            pbox = REGION_RECTS(shape);
+         nbox--;
+         pbox++)
+    {
+       if (pbox->x1 < x && pbox->x2 > x) {
+           d = pbox->y1 - y;
+           if (d >= 0) {
+               d *= d;
+               if (d < min) {
+                   *px = x;
+                   *py = pbox->y1 + 1;
+                   min = d;
+               }
+           } else {
+               d = pbox->y2 - y; d *= d;
+               if (d < min) {
+                   *px = x;
+                   *py = pbox->y2 - 1;
+                   min = d;
+               }
+           }
 	}
-	else if (x < box.x1)
-	{
-	    incx = 1;
-	    x = *px;
-	    y += incy;
-	    if (y >= box.y2)
-	    {
-		incy = -1;
-		y = *py - 1;
+       else if (pbox->y1 < y && pbox->y2 > y) {
+           d = pbox->x1 - x;
+           if (d >= 0) {
+               d *= d;
+               if (d < min) {
+                   *px = pbox->x1 + 1;
+                   *py = y;
+                   min = d;
+               }
+           } else {
+               d = pbox->x2 - x; d *= d;               
+               if (d < min) {
+                   *px = pbox->x2 - 1;
+                   *py = y;
+                   min = d;
+               }
+           }
+           
+       } else {
+           dx2 = pbox->x1 - x; 
+           if (dx2 >= 0) {
+               dx2 *= dx2;
+               x_r = pbox->x1 + 1;
+           } else {
+               dx2 = pbox->x2 - x; dx2 *= dx2;
+               x_r = pbox->x2 - 1;
+           }
+           dy2 = pbox->y1 - y; 
+           if (dy2 >= 0) {
+               dy2 *= dy2;
+               y_r = pbox->y1 + 1;
+           } else {
+               dy2 = pbox->y2 - y; dy2 *= dy2;
+               y_r = pbox->y2 - 1;
+           }
+           if ((d = dx2 + dy2) < min) {
+               *px = x_r;
+               *py = y_r;
+               min = d;
 	    }
-	    else if (y < box.y1)
-		return; /* should never get here! */
 	}
-    } while (!RegionContainsPoint(shape, x, y, &box));
-    *px = x;
-    *py = y;
+     }
 }
 
 static void