BUG. Forgot to initialise pointer to NULL.

src/lagrangian/intermediate/particleForces/particleForces.C

@@ -61,6 +61,7 @@ Foam::particleForces::particleForces
     dict_(dict.subDict("particleForces")),
     g_(g),
     gradUPtr_(NULL),
+    HdotGradHInterPtr_(NULL),
     gravity_(dict_.lookup("gravity")),
     virtualMass_(dict_.lookup("virtualMass")),
     Cvm_(0.0),
@@ -88,6 +89,7 @@ Foam::particleForces::particleForces(const particleForces& f)
     dict_(f.dict_),
     g_(f.g_),
     gradUPtr_(f.gradUPtr_),
+    HdotGradHInterPtr_(f.HdotGradHInterPtr_),
     gravity_(f.gravity_),
     virtualMass_(f.virtualMass_),
     Cvm_(f.Cvm_),