[API] added warning and assertion to findContainingProcess for points out of domain

src/pe/BlockFunctions.h

@@ -45,12 +45,20 @@ bool hasNeighborOwner(const BlockT& block, const Owner& owner)
  * Looks through all neighboring blocks to find the one whose AABB contains \a pt.
  * Also checks if \a pt is located in the block itself.
  * Returns -1 if no valid block is found otherwise the process rank of the containing block is returned.
+ *
+ * \attention If periodic boundaries are used you have to make sure the point is mapped to the domain before calling this function!
  */
 template <class BlockT>
-Owner findContainingProcess(const BlockT& block, math::Vector3<real_t> pt)
+Owner findContainingProcess(const BlockT& block, const math::Vector3<real_t> pt)
 {
+   WALBERLA_DEBUG_SECTION()
+   {
+      auto pt2 = pt;
+      block.getBlockStorage().mapToPeriodicDomain(pt2);
+      WALBERLA_ASSERT_EQUAL(pt, pt2);
+   }
+
    if (block.getAABB().contains(pt)) return Owner(int_c(block.getProcess()), block.getId().getID());
-   if (!block.getBlockStorage().getDomain().contains(pt)) block.getBlockStorage().mapToPeriodicDomain(pt);
    for( uint_t i = uint_t(0); i != block.getNeighborhoodSize(); ++i )
    {
       if (block.getNeighborAABB(i).contains(pt)) return Owner(int_c(block.getNeighborProcess(i)), block.getNeighborId(i).getID());