Changing a user's power level can result in your own power level being lowered

[Xiretza]

Steps to reproduce

I tried to lower a problematic user's power level as follows:

1. click on their profile picture
2. select "Custom level" in the "Power level" dropdown
3. unrelated bug: try to enter -1, but the input does not accept -, so I either entered 0 or left the field blank
4. press enter
5. an m.room.power_levels event is sent, adding an entry for the user with level 0, and changing the entry for the own user from 100 to 50

For future reference:

event `$eOIZHbZLm0g4eCm1WGMQ47qrLfkweOzhmkAyY2D9FQ0` in `!H55QZaxP7zgghhx48z:computer.surgery`

{
  "type": "m.room.power_levels",
  "sender": "@xiretza:xiretza.xyz",
  "content": {
    "events": {
      "im.vector.modular.widgets": 50,
      "m.reaction": 0,
      "m.room.avatar": 50,
      "m.room.canonical_alias": 50,
      "m.room.encryption": 100,
      "m.room.history_visibility": 50,
      "m.room.name": 50,
      "m.room.pinned_events": 50,
      "m.room.power_levels": 50,
      "m.room.redaction": 0,
      "m.room.server_acl": 50,
      "m.room.tombstone": 100,
      "m.room.topic": 50,
      "m.space.child": 50
    },
    "users": {
      "@amanda:graven.dev": 50,
      "@benjamin:computer.surgery": 50,
      "@charles:computer.surgery": 100,
      "@erikj:jki.re": 50,
      "@jplatte:flipdot.org": 100,
      "@jplatte:matrix.org": 0,
      "@levans:safaradeg.net": 50,
      "@ruma_mod:flipdot.org": 50,
      "@tanriol:matrix.org": 50,
      "@tanriol:mozilla.org": 50,
      "@timokoesters:fachschaften.org": 50,
      "@xiretza:xiretza.xyz": 50,
      "@thedarkknightx:matrix.org": 0
    }
  },
  "state_key": "",
  "origin_server_ts": 1676208005679,
  "unsigned": {
    "replaces_state": "$dkAAOyNp-a9Fk7OHsi78O3tladXAQ1r8p32HnetUnRU",
    "prev_content": {
      "events": {
        "im.vector.modular.widgets": 50,
        "m.reaction": 0,
        "m.room.avatar": 50,
        "m.room.canonical_alias": 50,
        "m.room.encryption": 100,
        "m.room.history_visibility": 50,
        "m.room.name": 50,
        "m.room.pinned_events": 50,
        "m.room.power_levels": 50,
        "m.room.redaction": 0,
        "m.room.server_acl": 50,
        "m.room.tombstone": 100,
        "m.room.topic": 50,
        "m.space.child": 50
      },
      "users": {
        "@amanda:graven.dev": 50,
        "@benjamin:computer.surgery": 50,
        "@charles:computer.surgery": 100,
        "@erikj:jki.re": 50,
        "@jplatte:flipdot.org": 100,
        "@jplatte:matrix.org": 0,
        "@levans:safaradeg.net": 50,
        "@ruma_mod:flipdot.org": 50,
        "@tanriol:matrix.org": 50,
        "@tanriol:mozilla.org": 50,
        "@timokoesters:fachschaften.org": 50,
        "@xiretza:xiretza.xyz": 100
      }
    },
    "prev_sender": "@jplatte:flipdot.org",
    "age": 3147
  },
  "event_id": "$eOIZHbZLm0g4eCm1WGMQ47qrLfkweOzhmkAyY2D9FQ0",
  "room_id": "!H55QZaxP7zgghhx48z:computer.surgery"
}

Outcome

What did you expect?

Changing another user's power level does not demote me from Admin to Moderator.

What happened instead?

I think the latest change to m.room.power_levels before this happened may have been my promotion from 50 to 100, so maybe that was undone for some reason?

Operating system

Arch Linux

Application version

Element version: 1.11.20, Olm version: 3.2.12

How did you install the app?

No response

Homeserver

No response

Will you send logs?

Yes

[t3chguy]

Related #19285 #22178