add region intersect

common/pixman-region.h

@@ -67,6 +67,9 @@ pixman_bool_t           pixman_region_union              (pixman_region16_t *new
 pixman_bool_t           pixman_region_subtract           (pixman_region16_t *reg_d,
                                                           pixman_region16_t *reg_m,
                                                           pixman_region16_t *reg_s);
+pixman_bool_t           pixman_region_intersect          (pixman_region16_t *new_reg,
+                                                          pixman_region16_t *reg1,
+                                                          pixman_region16_t *reg2);
 pixman_box16_t *        pixman_region_rectangles         (pixman_region16_t *region,
                                                           int               *n_rects);
 

xrdp/xrdp.h

@@ -175,8 +175,9 @@ xrdp_region_delete(struct xrdp_region* self);
 int APP_CC
 xrdp_region_add_rect(struct xrdp_region* self, struct xrdp_rect* rect);
 int APP_CC
-xrdp_region_subtract_rect(struct xrdp_region* self,
-                          struct xrdp_rect* rect);
+xrdp_region_subtract_rect(struct xrdp_region* self, struct xrdp_rect* rect);
+int APP_CC
+xrdp_region_intersect_rect(struct xrdp_region* self, struct xrdp_rect* rect);
 int APP_CC
 xrdp_region_get_rect(struct xrdp_region* self, int index,
                      struct xrdp_rect* rect);

xrdp/xrdp_region.c

@@ -91,6 +91,26 @@ xrdp_region_subtract_rect(struct xrdp_region *self, struct xrdp_rect *rect)
     return 0;
 }
 
+/*****************************************************************************/
+/* returns error */
+int APP_CC
+xrdp_region_intersect_rect(struct xrdp_region* self, struct xrdp_rect* rect)
+{
+    struct pixman_region16 lreg;
+
+    pixman_region_init_rect(&lreg, rect->left, rect->top,
+                            rect->right - rect->left,
+                            rect->bottom - rect->top);
+    if (!pixman_region_intersect(self->reg, self->reg, &lreg))
+    {
+        pixman_region_fini(&lreg);
+        return 1;
+    }
+    pixman_region_fini(&lreg);
+    return 0;
+}
+
+
 /*****************************************************************************/
 /* returns error */
 int APP_CC