Fix #3401 warning on multiple solid

- PartDesign only uses the first result shape
  of an operation and discards the rest without
  warning.

- this also fixes #1707

src/Mod/PartDesign/App/FeatureTransformed.cpp

@@ -331,6 +331,7 @@ App::DocumentObjectExecReturn *Transformed::execute(void)
                         // lets check if the result is a solid
                         if (current.IsNull())
                             return new App::DocumentObjectExecReturn("Resulting shape is not a solid", *o);
+
                         /*std::vector<TopoDS_Shape>::const_iterator individualIt;
                         for (individualIt = individualTools.begin(); individualIt != individualTools.end(); ++individualIt)
                         {
@@ -377,6 +378,11 @@ App::DocumentObjectExecReturn *Transformed::execute(void)
     for (rej_it_map::const_iterator it = nointersect_trsfms.begin(); it != nointersect_trsfms.end(); ++it)
         for (trsf_it::const_iterator it2 = it->second.begin(); it2 != it->second.end(); ++it2)
             rejected[it->first].push_back(**it2);
+
+    int solidCount = countSolids(support);
+    if (solidCount > 1) {
+        return new App::DocumentObjectExecReturn("Transformed: Result has multiple solids. Check parameters.");
+    }
 
     this->Shape.setValue(getSolid(support));