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