refs #10693. Relax restrictions.

I think these original restrictions made sense, but currently LoadSQW is not loading workspaces in the HKL frame, and therefore this restriction is going to prove a problem for beta testers.

I've set it to be a warning only if AxisCheck=False.

Code/Mantid/Framework/PythonInterface/plugins/algorithms/WorkflowAlgorithms/CutMD.py

@@ -175,8 +175,6 @@ def replace(self, entry):
 
     def __verify_input_workspace(self, to_cut):
         coord_system = to_cut.getSpecialCoordinateSystem()
-        if not coord_system == SpecialCoordinateSystem.HKL:
-            raise ValueError("Input Workspace must be in reciprocal lattice dimensions (HKL)")
 
         ndims = to_cut.getNumDims()
         if ndims < 3 or ndims > 4:
@@ -185,6 +183,10 @@ def __verify_input_workspace(self, to_cut):
         # Try to sanity check the order of the dimensions. This is important.
         axes_check = self.getProperty("CheckAxes").value
         if axes_check:
+
+            if not coord_system == SpecialCoordinateSystem.HKL:
+                raise ValueError("Input Workspace must be in reciprocal lattice dimensions (HKL)")
+
             predicates = ["^(H.*)|(\\[H,0,0\\].*)$","^(K.*)|(\\[0,K,0\\].*)$","^(L.*)|(\\[0,0,L\\].*)$"]  
             n_crystallographic_dims = __builtin__.min(3, ndims)
             for i in range(n_crystallographic_dims):

Code/Mantid/Framework/PythonInterface/test/python/mantid/api/CutMDTest.py

@@ -26,7 +26,7 @@ def test_exec_throws_if_not_a_hkl_workspace(self):
         test_md = CreateMDWorkspace(Dimensions=3, Extents=[-10,10,-10,10,-10,10], Names="A,B,C", Units="U,U,U")
         # Explicitly set the coordinate system to lab Q.
         SetSpecialCoordinates(InputWorkspace=test_md, SpecialCoordinates='Q (lab frame)')
-        self.assertRaises(RuntimeError, CutMD, InputWorkspace=test_md, OutputWorkspace="out_ws", P1Bin=[0.1], P2Bin=[0.1], P3Bin=[0.1], CheckAxes=False)
+        self.assertRaises(RuntimeError, CutMD, InputWorkspace=test_md, OutputWorkspace="out_ws", P1Bin=[0.1], P2Bin=[0.1], P3Bin=[0.1], CheckAxes=True)
 
     def test_exec_throws_if_set_to_be_a_hkl_workspace_but_with_missaligned_dimension_names(self):
         test_md = CreateMDWorkspace(Dimensions=3, Extents=[-10,10,-10,10,-10,10], Names="K,H,L", Units="U,U,U") # K,H,L are the dimension names