[Bug]: problems adding categories results in removal of categories

[mnalis]

Summary

Sometimes, adding a category is not accepted, and attempt to re-try it destroy existing categories:

e.g. https://commons.wikimedia.org/w/index.php?title=File%3AFailing_facade%2C_Voltino.jpg&diff=1017366440&oldid=1017366181

Steps to reproduce

1. add image normally
2. in categories selection screen, find select several categories
3. ?
4. try to uncheck and check again some category
5. click "save"
6. observe toast "trying to update categories", but categories window doesn't close
7. look up at web page and see all categories (except one which was removed and re-added) removed from picture metadata

Expected behaviour

• window would successfully close after clicking "save"
• all selected categories would remain on the picture

Actual behaviour

• windows doesn't close
• even if visually in the app categories are selected, they are actually removed from metadata on Commons servers

Device name

Samsung Galaxy S23+

Android version

Android 14

Commons app version

5.2.0~2e05a58e8 (f-droid)

Device logs

Subject: fr.free.nrw.commons Crash Report

USER_COMMENT=null
APP_VERSION_CODE=1049
APP_VERSION_NAME=5.2.0
ANDROID_VERSION=14
PHONE_MODEL=SM-S916B
STACK_TRACE=Report requested by developer


editing categories fails, nukes categories

IS_SILENT=true
USER_CRASH_DATE=2025-04-04T19:41:30.231+02:00
REPORT_ID=91fc573e-580a-46ed-accb-82ef154e2bae

Screen-shots

small_Screen_Recording_20250404_194045_Commons.mp4

Would you like to work on the issue?

None