Dynamics AX 2012: orig() method fails on derived tables

Just found a bug in the table inheritance feature (kernel 6.0.1108.5781).

If you have a base table A with field B, and a derived table C with field D, then C.orig().B will return a strange value (or nil, depending on the field type).

In order to get the correct value, you will need to downcast C to A, and then call A.orig().B.

This is the job that reproes the issue:

static void reproOrigBug(Args _args)
{
    CompanyInfo     companyInfo;
    DirPartyTable   dirPartyTable;
 
    select firstOnly companyInfo;
 
    info(companyInfo.orig().DataArea);
    info(companyInfo.orig().Name);
 
    dirPartyTable = companyInfo as DirPartyTable;
    info(dirPartyTable.orig().Name);
}

And this is the output:

I will report the issue to MS Support.

Table inheritance and collection objects

Be aware that there is an issue with storing child table records in collection objects like List.

If you have a table hierarchy and add a child table record to a List and then try to get it back, information from parent tables is lost, along with InstanceRelationType field value.

The following job reproes the issue:

static void tableInheritanceAndListBug(Args _args)
{
    CompanyInfo     companyInfo;
    List            companyInfoList;
    ListEnumerator  companyInfoEnumerator;
 
    companyInfoList = new List(Types::Record);
 
    select firstOnly companyInfo;
 
    info(strFmt(
        "Orig: RecId: %1, Name: %2, InstanceRelationType: %3",
        companyInfo.RecId,
        companyInfo.Name,
        companyInfo.InstanceRelationType));
 
    companyInfoList.addEnd(companyInfo);
 
    companyInfoEnumerator = companyInfoList.getEnumerator();
    if (companyInfoEnumerator.moveNext())
    {
        companyInfo = companyInfoEnumerator.current();
        info(strFmt(
            "List: RecId: %1, Name: %2, InstanceRelationType: %3",
            companyInfo.RecId,
            companyInfo.Name,
            companyInfo.InstanceRelationType));
    }
}

Output:
Orig: RecId: 5637151316, Name: Contoso Entertainment Systems - E&G Division, InstanceRelationType: 41
List: RecId: 5637151316, Name: , InstanceRelationType: 0

The workaround is to use buf2con function to convert the table buffer to a container, save the container in the list and finally use con2buf when fetching the value with enumerator.

static void tableInheritanceAndListBugWorkaround(Args _args)
{
    CompanyInfo     companyInfo;
    List            companyInfoList;
    ListEnumerator  companyInfoEnumerator;
 
    companyInfoList = new List(Types::Container);
 
    select firstOnly companyInfo;
 
    info(strFmt(
        "Orig: RecId: %1, Name: %2, InstanceRelationType: %3",
        companyInfo.RecId,
        companyInfo.Name,
        companyInfo.InstanceRelationType));
 
    companyInfoList.addEnd(buf2Con(companyInfo));
 
    companyInfoEnumerator = companyInfoList.getEnumerator();
    if (companyInfoEnumerator.moveNext())
    {
        companyInfo = con2Buf(companyInfoEnumerator.current());
        info(strFmt(
            "List: RecId: %1, Name: %2, InstanceRelationType: %3",
            companyInfo.RecId,
            companyInfo.Name,
            companyInfo.InstanceRelationType));
    }
}

Output:
Orig: RecId: 5637151316, Name: Contoso Entertainment Systems - E&G Division, InstanceRelationType: 41
List: RecId: 5637151316, Name: Contoso Entertainment Systems - E&G Division, InstanceRelationType: 41

UPDATE: the bugs is reported to MS Support