Fixed a bug in an assertion in the HTKMLFReader pertaining checking for distributed minibatch reading support

DataReader/HTKMLFReader/HTKMLFReader.cpp

@@ -643,7 +643,7 @@ namespace Microsoft { namespace MSR { namespace CNTK {
         void HTKMLFReader<ElemType>::StartDistributedMinibatchLoop(size_t mbSize, size_t epoch, size_t subsetNum, size_t numSubsets, size_t requestedEpochSamples /*= requestDataSize*/)
         {
             assert(subsetNum < numSubsets);
-            assert(this->SupportsDistributedMBRead() || ((subsetNum == 0) && (numSubsets == 1)));
+            assert(((subsetNum == 0) && (numSubsets == 1)) || this->SupportsDistributedMBRead());
 
             m_mbSize = mbSize;
 

DataReader/HTKMLFReader/HTKMLFReader.h

@@ -182,7 +182,7 @@ public:
 
     virtual bool SupportsDistributedMBRead() const override
     {
-        return m_frameSource->supportsbatchsubsetting();
+        return ((m_frameSource != nullptr) && m_frameSource->supportsbatchsubsetting());
     }
 
     virtual void StartDistributedMinibatchLoop(size_t mbSize, size_t epoch, size_t subsetNum, size_t numSubsets, size_t requestedEpochSamples = requestDataSize) override;