Description Egidijus Vaisnora 2010-09-10 07:38:07 EDT

Cloned from: 316887: Databinding & CDO Notifications
https://bugs.eclipse.org/bugs/show_bug.cgi?id=316887

Build Identifier: 

Situation at the moment:

- CDO fires notifications before the conflict resolver gets called during invalidation.
- Databinding relies on correct notifications fired.

As an example take two transaction T1 and T2. The model contains an object O1 that has a many reference list to other objects. The list contains following elements:

[a,b,c,d,e,f,g]

Within transaction T1 the operation MOVE 0 -> 6 is executed. No commit at the moment.
Within transaction T2 the operation REMOVE 2 is executed. No commit at the moment.

Situation after the two operations:

T1: [b,c,d,e,f,g,a]
T2: [a,b,d,e,f,g]

Then commit T1. T2 gets the invalidation. The object containing the list is marked as conflict. Next step is to create and fire the notification. The binding which has added an adapter to the object O1 to synchronize the model and the target list gets the MOVE 0->6 notification. But there is no element at index 6 what causes an IndexOutOfBounds exception. The databinding has an inconsistent state.

After the notifications are distributed the conflict resolver is called. which solves the conflict.

As there are many more such examples it would be better first call the conflict resolver and afterwards fire the notification. Of course a mechanism to patch the notifications should be provided.

Reproducible: Always