Correctly handle empty rects on region initialization.

include/regionstr.h

@@ -250,10 +250,26 @@ extern RegDataRec miBrokenData;
 #define REGION_INIT(_pScreen, _pReg, _rect, _size) \
 { \
     REGION_SCREEN(_pScreen); \
+    if (_rect) \
+    { \
         (_pReg)->extents = *(_rect); \
         (_pReg)->data = (RegDataPtr)NULL; \
+    } \
+    else \
+    { \
+        (_pReg)->extents = miEmptyBox; \
+        if (((_size) > 1) && ((_pReg)->data = \
+                             (RegDataPtr)xalloc(REGION_SZOF(_size)))) \
+        { \
+            (_pReg)->data->size = (_size); \
+            (_pReg)->data->numRects = 0; \
+        } \
+        else \
+            (_pReg)->data = &miEmptyData; \
+    } \
  }
 
+
 #define REGION_UNINIT(_pScreen, _pReg) \
 { \
     REGION_SCREEN(_pScreen); \