Re #8637. Clone the input workspace if filtering or masking.

Avoids the input workspace potentially being changed by the algorithm.
mantidproject · Jan 30, 2014 · c261608 · c261608
1 parent ae6eab9
commit c261608
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Showing 2 changed files with 20 additions and 3 deletions.
diff --git a/Code/Mantid/Framework/WorkflowAlgorithms/inc/MantidWorkflowAlgorithms/StepScan.h b/Code/Mantid/Framework/WorkflowAlgorithms/inc/MantidWorkflowAlgorithms/StepScan.h
@@ -49,6 +49,7 @@ namespace WorkflowAlgorithms
     void exec();
 
     DataObjects::EventWorkspace_sptr getMonitorWorkspace(API::MatrixWorkspace_sptr inputWS);
+    DataObjects::EventWorkspace_sptr cloneInputWorkspace(API::Workspace_sptr inputWS);
     void runMaskDetectors(API::MatrixWorkspace_sptr inputWS, API::MatrixWorkspace_sptr maskWS);
     void runFilterByXValue(API::MatrixWorkspace_sptr inputWS, const double xmin, const double xmax);
   };

diff --git a/Code/Mantid/Framework/WorkflowAlgorithms/src/StepScan.cpp b/Code/Mantid/Framework/WorkflowAlgorithms/src/StepScan.cpp
@@ -73,16 +73,22 @@ namespace WorkflowAlgorithms
     // TODO: How will this work for live data???
     DataObjects::EventWorkspace_sptr monitorWorkspace = getMonitorWorkspace(inputWorkspace);
 
-    // If the MaskWorkspace property has been set, run the MaskDetectors algorithm
+    // If any of the filtering properties have been set, clone the input workspace
     MatrixWorkspace_sptr maskWS = getProperty("MaskWorkspace");
+    const double xmin = getProperty("XMin");
+    const double xmax = getProperty("XMax");
+    if ( maskWS || !isEmpty(xmin) || !isEmpty(xmax) )
+    {
+      inputWorkspace = cloneInputWorkspace(inputWorkspace);
+    }
+
+    // If the MaskWorkspace property has been set, run the MaskDetectors algorithm
     if ( maskWS )
     {
       runMaskDetectors(inputWorkspace, maskWS);
     }
 
     // If a restricted X range has been set, handle that
-    const double xmin = getProperty("XMin");
-    const double xmax = getProperty("XMax");
     if ( !isEmpty(xmin) || !isEmpty(xmax) )
     {
       runFilterByXValue(inputWorkspace, xmin, xmax);
@@ -133,6 +139,16 @@ namespace WorkflowAlgorithms
     return monitorWorkspace;
   }
 
+  DataObjects::EventWorkspace_sptr StepScan::cloneInputWorkspace(API::Workspace_sptr inputWS)
+  {
+    IAlgorithm_sptr clone = createChildAlgorithm("CloneWorkspace");
+    clone->setProperty("InputWorkspace",inputWS);
+    clone->executeAsChildAlg();
+
+    Workspace_sptr temp = clone->getProperty("OutputWorkspace");
+    return boost::static_pointer_cast<DataObjects::EventWorkspace>(temp);
+  }
+
   /** Runs MaskDetectors as a child algorithm on the input workspace.
    *  @param inputWS The input workspace
    *  @param maskWS  A masking workspace