The file rename message is "Hello world!" instead of a general file rename success message

[ilieandriuta]

Steps To Reproduce

1. Add a file in File Manager
2. Select it by ticking the box in the left of it
3. Click 'Rename' button
4. Change/ update the file name
5. Press Enter key
6. Observe the rename success message

Expected results

The success message is "File renamed" or just "Renamed".

Actual results

The success message says "Hello world!".

Screenshots

Environment:

• OS: Windows 11 Pro
• Browser: Firefox 152
• XWiki version: 18.4.2 on PostgreSQL 17/ Tomcat 11.0.23, and 18.4.2 on Jetty/ HSQL
• Java version: 25
• App version: File Manager Pro 2.9.1

[abrassat]

The root cause for this issue was a logic bug in rendering the notification, where the localization string was used as a localization key. The issue is only affecting 18.4.x because the localization js API was changed to return null when asking for a non-existent key, instead of returning the key itself.