[DAFFODIL-2262] occursCountKind 'expression' should avoid separator suppression, but does not.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.0
• Fix Version/s: 2.5.0
• Component/s: Back End
• Assignee: Dave Thompson
• Reporter: Mike Beckerle
• Created: 30/Dec/19 18:01
• Updated: 20/May/21 12:33
• Resolved: 02/Jan/20 16:28

Description

Reported on users mailing list.

Section 14.2.2 of the DFDL specification says this:

When dfdl:occursCountKind is 'expression' the number of occurrences is given by dfdl:occursCount and exactly that many occurrences are always expected along with their separators. The dfdl:separatorSuppressionPolicy is not applicable and the implied behaviour is 'never'.

The below schema has dfdl:occursCountKind="expression" and yet I am not observing the expected implied behavior of 'never'. That is, with this input:

header1,header2
 a,

After parsing and then unparsing I get this:

header1,header2
 a

Notice that the comma separator has been suppressed after ‘a’ but the specification says that the implied behavior is to never suppress the separator. This seems like a bug to me. Do you agree? 

<xs:element name="input">
     <xs:complexType>
         <xs:sequence dfdl:separator="%NL;" dfdl:separatorPosition="infix">
             <xs:element name="header">
                 <xs:complexType>
                     <xs:sequence dfdl:separator="," dfdl:separatorPosition="infix"  dfdl:separatorSuppressionPolicy="anyEmpty">
                         <xs:element name="title" maxOccurs="unbounded" type="xs:string" />
                     </xs:sequence>
                 </xs:complexType>
             </xs:element>
             <xs:element name="row" maxOccurs="unbounded">
                 <xs:complexType>
                     <xs:sequence dfdl:separator="," dfdl:separatorPosition="infix" dfdl:separatorSuppressionPolicy="anyEmpty">
                         <xs:element name="field" maxOccurs="unbounded" type="xs:string"
                             dfdl:occursCount="{ fn:count(../../header/title) }"
                             dfdl:occursCountKind="expression" />
                     </xs:sequence>
                 </xs:complexType>
             </xs:element>
         </xs:sequence>
     </xs:complexType>
 </xs:element>