Additional check to gather attributes for rows without tagname

If xpath specifies that a row should be output without a root tag
queryAttrList may never be called at the row level.  If so, gather
the attributes for nested records later, when queryAttrList is called
for one of the nested records.

Signed-off-by: Anthony Fishbeck <Anthony.Fishbeck@lexisnexis.com>

common/fileview2/fvsource.cpp

@@ -482,6 +482,8 @@ void DataSourceMetaData::gatherAttributes()
 
 const IntArray &DataSourceMetaData::queryAttrList(unsigned column)
 {
+    if (!gatheredAttributes)
+        gatherAttributes();
     return fields.item(column).nestedAttributes;
 }