[OAK-9567] Avoid NullPointerException in ReadWriteVersionManager.removeVersion

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.40.0
• Fix Version/s: 1.42.0, 1.22.17
• Component/s: core
• Assignee: Stefan Egli
• Reporter: Stefan Egli
• Created: 08/Sep/21 14:40
• Updated: 18/Aug/23 05:43
• Resolved: 15/Sep/21 08:36

Description

On occasion the following NullPointerException can be witnessed:

java.lang.NullPointerException: null
	at org.apache.jackrabbit.oak.plugins.version.ReadWriteVersionManager.removeVersion(ReadWriteVersionManager.java:208)
	at org.apache.jackrabbit.oak.plugins.version.VersionStorageEditor.childNodeDeleted(VersionStorageEditor.java:122)

This points to some inconsistency wrt jcr:predecessors and jcr:successors.

As a minimal step we should avoid the null pointer and add more logging - to help ultimately track down what causes the inconsistency.

Issue Links

• is related to: OAK-5193 Version tree may become inconsistent after removing a version
• links to: GitHub Pull Request #363
• links to: GitHub Pull Request #1077