Displace box definition checking to avoid hang-up in parallel

src/mesh/CartesianMeshBuilder.cpp

@@ -125,7 +125,6 @@ CartesianMeshBuilder::CartesianMeshBuilder(const TinyVector<Dimension>& a,
                                            const TinyVector<Dimension>& b,
                                            const TinyVector<Dimension, uint64_t>& size)
 {
-  if (parallel::rank() == 0) {
   TinyVector lenght = b - a;
   for (size_t i = 0; i < Dimension; ++i) {
     if (lenght[i] == 0) {
@@ -133,6 +132,7 @@ CartesianMeshBuilder::CartesianMeshBuilder(const TinyVector<Dimension>& a,
     }
   }
 
+  if (parallel::rank() == 0) {
     TinyVector<Dimension> corner0 = a;
     TinyVector<Dimension> corner1 = b;