Fixed error in long range correction with force groups (#3261)

openmmapi/src/CustomNonbondedForce.cpp

@@ -53,6 +53,8 @@ CustomNonbondedForce::CustomNonbondedForce(const string& energy) : energyExpress
 
 CustomNonbondedForce::CustomNonbondedForce(const CustomNonbondedForce& rhs) {
     // Copy everything and deep copy the tabulated functions
+    setForceGroup(rhs.getForceGroup());
+    setName(rhs.getName());
     energyExpression = rhs.energyExpression;
     nonbondedMethod = rhs.nonbondedMethod;
     cutoffDistance = rhs.cutoffDistance;

platforms/common/src/CommonKernels.cpp

@@ -1776,6 +1776,8 @@ public:
             cc(cc), longRangeCoefficient(longRangeCoefficient), longRangeCoefficientDerivs(longRangeCoefficientDerivs), force(force) {
     }
     double computeForceAndEnergy(bool includeForces, bool includeEnergy, int groups) {
+        if ((groups&(1<<force->getForceGroup())) == 0)
+            return 0;
         cc.getWorkThread().flush();
         Vec3 a, b, c;
         cc.getPeriodicBoxVectors(a, b, c);