Wall source momenta must be specified for spatial components only.

So we don't break existing scripts, allow momentum in time direction as well, but only if zero.
Fail early, so do the check in setup()

Hadrons/Modules/MSource/Wall.hpp

@@ -122,6 +122,15 @@ void TWall<FImpl>::setup(void)
     envCache(Lattice<iScalar<vInteger>>, tName_, 1, envGetGrid(LatticeComplex));
     envCacheLat(LatticeComplex, momphName_);
     envTmpLat(LatticeComplex, "coor");
+    auto  &src = envGet(PropagatorField, getName());
+    const auto NumDims = src.Grid()->Dimensions();
+    // Don't break existing scripts as long as they specified zero momentum in time dimension
+    std::vector<Real> p = strToVec<Real>(par().mom);
+    if (!(p.size() == NumDims - 1 || (p.size() == NumDims && p[NumDims - 1] == 0)))
+    {
+        HADRONS_ERROR(Size, "momentum has " + std::to_string(p.size())
+                      + " components (must have " + std::to_string(NumDims - 1) + ")");
+    }
 }
 
 // execution ///////////////////////////////////////////////////////////////////
@@ -143,7 +152,8 @@ void TWall<FImpl>::execute(void)
         envGetTmp(LatticeComplex, coor);
         p  = strToVec<Real>(par().mom);
         ph = Zero();
-        for(unsigned int mu = 0; mu < env().getNd(); mu++)
+        const auto NumDims = src.Grid()->Dimensions();
+        for(unsigned int mu = 0; mu < NumDims - 1; mu++)
         {
             LatticeCoordinate(coor, mu);
             ph = ph + (p[mu]/env().getDim(mu))*coor;