Merge remote-tracking branch 'origin/bugfix/9419_instrumentview_exception_on_replace'

Code/Mantid/MantidPlot/src/Mantid/InstrumentWidget/InstrumentActor.cpp

@@ -79,9 +79,6 @@ m_failedColor(200,200,200)
   // set up data ranges and colours
   setUpWorkspace(sharedWorkspace, scaleMin, scaleMax);
 
-  /// Keep the pointer to the detid2index map
-  m_detid2index_map = sharedWorkspace->getDetectorIDToWorkspaceIndexMap();
-
   Instrument_const_sptr instrument = getInstrument();
 
   // If the instrument is empty, maybe only having the sample and source
@@ -172,6 +169,9 @@ void InstrumentActor::setUpWorkspace(boost::shared_ptr<const Mantid::API::Matrix
   auto wsValidator = Mantid::API::CommonBinsValidator();
   m_ragged = ! wsValidator.isValid(sharedWorkspace).empty();
 
+  /// Keep the pointer to the detid2index map
+  m_detid2index_map = sharedWorkspace->getDetectorIDToWorkspaceIndexMap();
+
 }
 
 /** Used to set visibility of an actor corresponding to a particular component
@@ -1066,8 +1066,6 @@ void InstrumentActor::setDataMinMaxRange(double vmin, double vmax)
 
 void InstrumentActor::setDataIntegrationRange(const double& xmin,const double& xmax)
 {
-  if (!getWorkspace()) return;
-
   m_BinMinValue = xmin;
   m_BinMaxValue = xmax;
 

Code/Mantid/MantidPlot/src/Mantid/InstrumentWidget/InstrumentWindow.cpp

@@ -720,12 +720,20 @@ void InstrumentWindow::afterReplaceHandle(const std::string& wsName,
   {
     if (m_instrumentActor)
     {
-      // try to detect if the instrument changes with the workspace
+      // Check if it's still the same workspace underneath (as well as having the same name)
       auto matrixWS = boost::dynamic_pointer_cast<const MatrixWorkspace>( workspace );
+      bool sameWS = false;
+      try {
+        sameWS = ( matrixWS == m_instrumentActor->getWorkspace() );
+      } catch (std::runtime_error&) {
+        // Carry on, sameWS should stay false
+      }
+
+      // try to detect if the instrument changes (unlikely if the workspace hasn't, but theoretically possible)
       bool resetGeometry = matrixWS->getInstrument()->getNumberDetectors() != m_instrumentActor->ndetectors();
 
-      // if instrument doesn't change keep the scaling
-      if ( !resetGeometry )
+      // if workspace and instrument don't change keep the scaling
+      if ( sameWS && !resetGeometry )
       {
         m_instrumentActor->updateColors();
       }