Fix bug in writeData for ManagedRawFileWorkspace. Refs #5620

The call up to ManagedWorkspace was clearing the changed flag
so that the blocks were not marked as changed in the
ManagedRawFileWorkspace. The test did not show this as it only wrote to
the workspace once which would have just used the block in the MRU.

Code/Mantid/Framework/DataHandling/src/ManagedRawFileWorkspace2D.cpp

@@ -307,9 +307,11 @@ namespace Mantid
     void ManagedRawFileWorkspace2D::writeDataBlock(DataObjects::ManagedDataBlock2D *toWrite) const
     {
       Poco::ScopedLock<Poco::FastMutex> mutex(m_mutex);
+      // ManagedWorkspace2D resets the hasChanges flag but we need to make sure we keep track of it here as well
+      const bool blockHasChanged = toWrite->hasChanges();
       ManagedWorkspace2D::writeDataBlock(toWrite);
       int blockIndex = static_cast<int>(toWrite->minIndex() / m_vectorsPerBlock);
-      m_changedBlock[blockIndex] = toWrite->hasChanges();
+      m_changedBlock[blockIndex] = blockHasChanged;
     }
 
     /**

Code/Mantid/Framework/DataHandling/test/ManagedRawFileWorkspace2DTest.h

@@ -79,18 +79,23 @@ class ManagedRawFileWorkspace2DTest : public CxxTest::TestSuite
   void testChanges()
   {
     ManagedRawFileWorkspace2D ws(file);
-
-    MantidVec& y0 = ws.dataY(0);
-    y0[100] = 1234.;
-
-    MantidVec& y1000 = ws.dataY(1000);
-    y1000[200] = 4321.;
-
-    TS_ASSERT_EQUALS( ws.dataY(0)[100], 1234. )
-    TS_ASSERT_EQUALS( ws.dataY(1000)[200], 4321. )
-    TS_ASSERT_EQUALS( ws.readY(0)[100], 1234. )
-    TS_ASSERT_EQUALS( ws.readY(1000)[200], 4321. )
-
+    // Need to ensure that the number of writes is greater than the MRUList size
+    // so that we check the read/write from the file
+    // There is no public API to find the size so this will have to do.
+    const size_t nhist = 400;
+    for(size_t i = 0; i < nhist; ++i)
+    {
+      MantidVec& y0 = ws.dataY(i);
+      y0[0] = 100.0;
+    }
+
+    // Check that we have actually changed it
+    for(size_t i = 0; i < nhist; ++i)
+    {
+      const MantidVec& y0 = ws.readY(i);
+      const std::string msg = "The first value at index " + boost::lexical_cast<std::string>(i) + " does not have the expected value.";
+      TSM_ASSERT_EQUALS(msg, y0[0], 100.0 );
+    }
   }
 
   // Test is taken from LoadRawTest