Saving a XWIki document using Java generates a very confusing result

Question

I spent the last week or so figuring out very strange behavior which I could not explain. I’m not sure if any sort of code would be helpful so I just explain what the situation is:

We have a class “caseClass” containing (among others) the following DBList:

Name = product

Pretty Name = product

Custom Display =

{{velocity}}
#set ($propertyClass = $object.getxWikiClass().get($name))
#if ($type == 'edit')
  {{html clean=false}}
    $doc.displayEdit($propertyClass, $prefix, $object)
  {{/html}}
#else
   #set($listMap=$propertyClass.getMapValues())
   #foreach($fieldKey in $object.getProperty($name).value)
      #set($fieldValue=$listMap.get($fieldKey).getValue())
      [[${fieldValue}>>$services.PropertyManager.getSourceURL(${fieldKey})]]
   #end
#end
{{/velocity}}

DisplayType = select

Multiple Select = true

Since of box = 10

Multiselect seperators = [] - empty

Join seperator = ,

Sort = none

Relational Storage = true

Cache = false

Hibernate Query =

SELECT idVarProp.value, CONCAT(codeVarProp.value, ' - ', naamVarProp.value, ' (', codeProdProp.value, ' - ', naamProdProp.value, ')') 
FROM BaseObject obj, StringProperty idVarProp, StringProperty codeVarProp, StringProperty naamVarProp, StringProperty idVarProdProp, 
BaseObject obj2, StringProperty idProdProp, StringProperty codeProdProp, StringProperty naamProdProp 
WHERE obj.className = 'PDCKlassen.VariantClass' AND 
obj2.className = 'PDCKlassen.ProductClass' AND 
idVarProp.id.id = obj.id AND idVarProp.id.name = 'identificatieString' AND 
codeVarProp.id.id = obj.id AND codeVarProp.id.name = 'codeVariant' AND 
naamVarProp.id.id = obj.id AND naamVarProp.id.name = 'naamVariant' AND 
idVarProdProp.id.id = obj.id AND idVarProdProp.id.name = 'product' AND 
idProdProp.id.id = obj2.id AND idProdProp.id.name = 'identificatieString' AND 
codeProdProp.id.id = obj2.id AND codeProdProp.id.name = 'productCode' AND 
naamProdProp.id.id = obj2.id AND naamProdProp.id.name = 'naam' AND 
idVarProdProp.value = idProdProp.value AND
obj.name <> 'PDCKlassen.VariantTemplate' AND obj2.name <> 'PDCKlassen.ProductTemplate' 
ORDER BY codeProdProp.value, codeVarProp.value

XWiki Class name = [] - empty

Id Field Name = [] - empty

Value Field Name = [] - empty

The functional side is obviously, that this field can contain 0 - n occurrences.

We have a java based listener that is used to save pages with one (exactly one) object of this class on the page with a version comment:

xwikiContext.getWiki().saveDocument(XWikiDocument, comment, true, xwikiContext)

The expectation is, that a new (minor) version of the page is saved with the aforementioned comment.

Situation 1: The object contains zero references (i.e. is empty)

the following a trace of what is happening:

Version 1.1 - This is the initial version After generating an event that saves the document (version 1.1) with comment "first comment" as described above the result is:

Version 1.2 - with the proper comment as passed by the save and as comment “first comment" After generating a second event that saves the document (version 1.2 this time) as above and as comment “second comment" the result is:

Version 1.2 - no change detected. The version comment is still “first comment”.

Manually editing the page and pressing save button, the result is:

Version 1.3 (minor edit selected) or Version 2.1 (minor edit not selected)

If I go back to the first step (as described after Version 1.1), the same result: the first minor version is saved, the second one is not saved.

I have checked everything up to that actual save in the XWiki class. I can see that the information passed to the saveDocument in the XWiki class is the ‘right’ data. I also tested this with minorEdit = false and this gives a similar result

Situation 2: The DBList contains one (or more) references (i.e. is not empty)

the following is happening:

Version 1.1 - This is the initial version

After generating an event that saves the document (version 1.1) as above with comment “first comment". The results is:

Version 1.2 - with the proper comment as passed by the save and as comment “first comment"

After generating a second listener event that saves the document (Version 1.2 this time) as above and as comment “second comment", the result is:

Version 1.3 - with the proper comment as passed by the second save and the comment “second comment”

I have looked for various aspects such as comparing object, sheets and whatnot but I could not detect any difference.

Solution

Until I decided to change “Relational Storage” to false. This resulted in the proper situation (described by Situation 2 - with an empty DBList as well as an non-empty DBList)

This solution will work in our situation but we prefer to have the Relation Storage selected (true) since we do not want to have any limitations on the size of the DBList.

Is there anyone who can explain this behavior or can confirm this is happening?