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Qt Version: 6.9.2
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Product Name: Inspiron 16 5640

# Insufficient error handling; revision checks disabled during ItemModifyJob

**Severity:** Medium-High  
**Area:** AgentBase / ResourceBase  

## Description
`ItemModifyJob` has `disableRevisionCheck()` calls with TODOs questioning where/how to handle errors. Disabling revision checks risks overwriting concurrent changes without detection.

## Evidence
/mnt/data/akonadi_extracted/akonadi/src/agentbase/resourcebase.cpp lines 691–696:

```
 688|     connect(transaction, &KJob::finished, d, &ResourceBasePrivate::changeCommittedResult);
 689| 
 690|     // Modify the items one-by-one, because STORE does not support mass RID change
 691|     for (const Item &item : items) {
 692|         auto job = new ItemModifyJob(item, transaction);
 693|         job->d_func()->setClean();
 694|         job->disableRevisionCheck(); // TODO: remove, but where/how do we handle the error?
 695|         job->setIgnorePayload(true); // we only want to reset the dirty flag and update the remote id
 696|     }
```

## Steps to Reproduce
1. Simulate concurrent modification to an `Item` while a resource executes `ItemModifyJob` with revision checks disabled.
2. Observe whether conflicting updates are accepted without error.

## Expected Behavior
Conflicting updates should be detected and surfaced to the caller; revision checks remain enabled or are replaced with safe conflict resolution.

## Actual Behavior
Revision checks are disabled; TODO indicates missing error handling path.

## Suggested Fix / Next Steps
- Reintroduce revision checks or implement optimistic concurrency with retries and conflict callbacks.
- Plumb explicit error handling paths where jobs currently suppress errors.
- Extend autotests to cover concurrent modification scenarios.