Make sure Region handles invalid rectangles

the boolean operation code assumes rects are valid and
could go into an infinite loop if not. make sure we
abort before that happens.

Bug: 5331198, 5334829
Change-Id: I8aa42b2e0b37238ec2434b794dd84c1a1b70f163

Author: pixelflinger

libs/ui/Region.cpp

@@ -479,6 +479,11 @@ void Region::boolean_operation(int op, Region& dst,
         const Region& lhs,
         const Rect& rhs, int dx, int dy)
 {
+    if (!rhs.isValid()) {
+        LOGE("Region::boolean_operation(op=%d) invalid Rect={%d,%d,%d,%d}",
+                op, rhs.left, rhs.top, rhs.right, rhs.bottom);
+    }
+
 #if VALIDATE_WITH_CORECG || VALIDATE_REGIONS
     boolean_operation(op, dst, lhs, Region(rhs), dx, dy);
 #else