Move away from deprecated nxs functions

Rather than `NXgetnextattr` use `NXgetnextattra` and error
out if an array is encountered.

Framework/DataHandling/src/LoadHelper.cpp

@@ -418,11 +418,22 @@ void LoadHelper::dumpNexusAttributes(NXhandle nxfileID,
   // Attributes
   NXname pName;
   int iLength, iType;
+  int rank;
+  int dims[4];
   int nbuff = 127;
   boost::shared_array<char> buff(new char[nbuff + 1]);
 
-  while (NXgetnextattr(nxfileID, pName, &iLength, &iType) != NX_EOD) {
+  while (NXgetnextattra(nxfileID, pName, &rank, dims, &iType) != NX_EOD) {
     g_log.debug() << indentStr << '@' << pName << " = ";
+    if (rank > 1) { // mantid only supports single value attributes
+      throw std::runtime_error(
+          "Encountered attribute with multi-dimensional array value");
+    }
+    iLength = dims[0]; // to clarify things
+    if (iType != NX_CHAR && iLength != 1) {
+      throw std::runtime_error("Encountered attribute with array value");
+    }
+
     switch (iType) {
     case NX_CHAR: {
       if (iLength > nbuff + 1) {

Framework/DataHandling/src/SaveToSNSHistogramNexus.cpp

@@ -18,7 +18,6 @@
 #include <boost/shared_ptr.hpp>
 #include <boost/scoped_array.hpp>
 #include <Poco/File.h>
-//#include <hdf5.h> //This is troublesome on multiple platforms.
 
 #include <cstdlib>
 #include <cstring>
@@ -649,15 +648,20 @@ int SaveToSNSHistogramNexus::WriteAttributes(int is_definition) {
   (void)is_definition;
 
   int status, i, attrLen, attrType;
+  int rank;
+  int dims[4];
   NXname attrName;
   void *attrBuffer;
 
   i = 0;
   do {
-    status = NXgetnextattr(inId, attrName, &attrLen, &attrType);
+    status = NXgetnextattra(inId, attrName, &rank, dims, &attrType);
     if (status == NX_ERROR)
       return NX_ERROR;
     if (status == NX_OK) {
+      if (rank != 1)
+        return NX_ERROR;
+      attrLen = dims[0];
       if (strcmp(attrName, "NeXus_version") &&
           strcmp(attrName, "XML_version") && strcmp(attrName, "HDF_version") &&
           strcmp(attrName, "HDF5_Version") && strcmp(attrName, "file_name") &&

Framework/Nexus/src/NexusClasses.cpp

@@ -83,12 +83,24 @@ std::string NXObject::name() const {
 void NXObject::getAttributes() {
   NXname pName;
   int iLength, iType;
+  int rank;
+  int dims[4];
   int nbuff = 127;
   boost::shared_array<char> buff(new char[nbuff + 1]);
-  while (NXgetnextattr(m_fileID, pName, &iLength, &iType) != NX_EOD) {
+
+  while (NXgetnextattra(m_fileID, pName, &rank, dims, &iType) != NX_EOD) {
     // std::cerr<<"--------------------------\n";
     // std::cerr<<"name="<<path()<<'\n';
     // std::cerr<<pName<<' ' <<iLength<<' '<<iType<<'\n';
+    if (rank > 1) { // mantid only supports single value attributes
+      throw std::runtime_error(
+          "Encountered attribute with multi-dimensional array value");
+    }
+    iLength = dims[0]; // to clarify things
+    if (iType != NX_CHAR && iLength != 1) {
+      throw std::runtime_error("Encountered attribute with array value");
+    }
+
     switch (iType) {
     case NX_CHAR: {
       if (iLength > nbuff + 1) {