cid#1371315 Missing move assignment operator

Change-Id: I9da0ffe856a0a40094c1c553bb2c5e05d8d3ef5d

drawinglayer/source/attribute/strokeattribute.cxx

@@ -107,6 +107,12 @@ namespace drawinglayer
             return *this;
         }
 
+        StrokeAttribute& StrokeAttribute::operator=(StrokeAttribute&& rCandidate)
+        {
+            mpStrokeAttribute = rCandidate.mpStrokeAttribute;
+            return *this;
+        }
+
         bool StrokeAttribute::operator==(const StrokeAttribute& rCandidate) const
         {
             // tdf#87509 default attr is always != non-default attr, even with same values

include/drawinglayer/attribute/strokeattribute.hxx

@@ -52,6 +52,7 @@ namespace drawinglayer
             StrokeAttribute();
             StrokeAttribute(const StrokeAttribute& rCandidate);
             StrokeAttribute& operator=(const StrokeAttribute& rCandidate);
+            StrokeAttribute& operator=(StrokeAttribute&& rCandidate);
             ~StrokeAttribute();
 
             // checks if the incarnation is default constructed