Fetch profiles fail to load certain relations because of invalid cycle detection in MetamodelGraphWalker. Attached test case.

Details:

Have 5 entities - Start, Via1, Via2, Mid and Finish with following relations (all LAZY):

Start n:1 Via1 n:1 Mid n:1 Finish
Start n:1 Via2 n:1 Mid n:1 Finish

Now, trying to use Fetch Profiles to load Start entity and all of its relations. I would expect Hibernate to execute following SQL select:

SELECT * FROM Start s
LEFT OUTER JOIN Via1 v1 (path Start-Via1)
LEFT OUTER JOIN Mid
JOIN Finish

LEFT OUTER JOIN Via2 (path Start-Via2)
LEFT OUTER JOIN Mid
JOIN Finish

Unfortunately, ic ompletely omits the second join from Mid to Finish, what I am getting is:

SELECT * FROM Start s
LEFT OUTER JOIN Via1 v1 (path Start-Via1)
LEFT OUTER JOIN Mid
JOIN Finish

LEFT OUTER JOIN Via2 (path Start-Via2)
LEFT OUTER JOIN Mid

I dug deeper into this and found cycle detection in MetamodelGraphWalker, line 144. Basically, when MetamodelGraphWalker detects a relation that has already been visited, it considers it a cycle. But in my case it is not a cycle - I just came to the same relation twice using two different paths.

From the user perspective, the fetch profiles seem to behave randomly - sometimes they fetch correct relations, sometimes they do not.

I believe there should be a better cycle detection.