[Bug] [25.0.0RC4] Custom background doesn't stay (404)

[PVince81]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• Nextcloud Server is running on 64bit capable CPU, PHP and OS.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Getting a 404 on a custom background: GET https://.../index.php/apps/theming/background

MariaDB [nextcloud]> select * from oc_preferences where userid='alice' and appid in ('dashboard', 'theming');
+--------+-----------+-------------------+-------------+
| userid | appid     | configkey         | configvalue |
+--------+-----------+-------------------+-------------+
| alice  | dashboard | firstRun          | 0           |
| alice  | theming   | background        | custom      |
| alice  | theming   | backgroundVersion | 1           |
+--------+-----------+-------------------+-------------+
3 rows in set (0.001 sec)

file "background.jpg" is missing on disk in "data/appdata_*/theming/alice"

Steps to reproduce

1. Create three users Alice, Bob and Charles
2. Login as Alice
3. Upload an image
4. Set that image as custom background
5. Go to files app and shift+refresh to see it

Expected behavior

Background appears and exists on disk

Installation method

No response

Operating system

No response

PHP engine version

No response

Web server

No response

Database engine version

No response

Is this bug present after an update or on a fresh install?

No response

Are you using the Nextcloud Server Encryption module?

No response

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

No response

List of activated Apps

N/A

Nextcloud Signing status

No response

Nextcloud Logs

{
  "reqId": "yGU73Yn4alZXEjEKqNf7",
  "level": 3,
  "time": "2022-10-14T07:50:24+00:00",
  "remoteAddr": "127.0.0.1",
  "user": "--",
  "app": "index",
  "method": "GET",
  "url": "/index.php/apps/theming/background?v=2",
  "message": "Call to a member function getUID() on null",
  "userAgent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 Safari/537.36",
  "version": "25.0.0.16",
  "exception": {
    "Exception": "Error",
    "Message": "Call to a member function getUID() on null",
    "Code": 0,
    "Trace": [
      {
        "function": "__construct",
        "class": "OCA\\Theming\\Controller\\UserThemeController",
        "type": "->",
        "args": [
          "theming",
          {
            "__class__": "OC\\AppFramework\\Http\\Request"
          },
          {
            "__class__": "OC\\AllConfig"
          },
          {
            "__class__": "OC\\User\\Session"
          },
          {
            "__class__": "OCA\\Theming\\Service\\ThemesService"
          },
          {
            "__class__": "OCA\\Theming\\ThemingDefaults"
          },
          {
            "__class__": "OCA\\Theming\\Service\\BackgroundService"
          }
        ]
      },
      {
        "file": "/srv/www/htdocs/server/lib/private/AppFramework/Utility/SimpleContainer.php",
        "line": 108,
        "function": "newInstanceArgs",
        "class": "ReflectionClass",
        "type": "->",
        "args": [
          [
            "theming",
            {
              "__class__": "OC\\AppFramework\\Http\\Request"
            },
            {
              "__class__": "OC\\AllConfig"
            },
            {
              "__class__": "OC\\User\\Session"
            },
            {
              "__class__": "OCA\\Theming\\Service\\ThemesService"
            },
            {
              "__class__": "OCA\\Theming\\ThemingDefaults"
            },
            {
              "__class__": "OCA\\Theming\\Service\\BackgroundService"
            }
          ]
        ]
      },
      {
        "file": "/srv/www/htdocs/server/lib/private/AppFramework/Utility/SimpleContainer.php",
        "line": 116,
        "function": "buildClass",
        "class": "OC\\AppFramework\\Utility\\SimpleContainer",
        "type": "->",
        "args": [
          {
            "__class__": "ReflectionClass",
            "name": "OCA\\Theming\\Controller\\UserThemeController"
          }
        ]
      },
      {
        "file": "/srv/www/htdocs/server/lib/private/AppFramework/Utility/SimpleContainer.php",
        "line": 133,
        "function": "resolve",
        "class": "OC\\AppFramework\\Utility\\SimpleContainer",
        "type": "->",
        "args": [
          "OCA\\Theming\\Controller\\UserThemeController"
        ]
      },
      {
        "file": "/srv/www/htdocs/server/lib/private/AppFramework/DependencyInjection/DIContainer.php",
        "line": 465,
        "function": "query",
        "class": "OC\\AppFramework\\Utility\\SimpleContainer",
        "type": "->",
        "args": [
          "OCA\\Theming\\Controller\\UserThemeController"
        ]
      },
      {
        "file": "/srv/www/htdocs/server/lib/private/AppFramework/DependencyInjection/DIContainer.php",
        "line": 437,
        "function": "queryNoFallback",
        "class": "OC\\AppFramework\\DependencyInjection\\DIContainer",
        "type": "->",
        "args": [
          "OCA\\Theming\\Controller\\UserThemeController"
        ]
      },
      {
        "file": "/srv/www/htdocs/server/lib/private/AppFramework/App.php",
        "line": 159,
        "function": "query",
        "class": "OC\\AppFramework\\DependencyInjection\\DIContainer",
        "type": "->",
        "args": [
          "OCA\\Theming\\Controller\\UserThemeController"
        ]
      },
      {
        "file": "/srv/www/htdocs/server/lib/private/Route/Router.php",
        "line": 298,
        "function": "main",
        "class": "OC\\AppFramework\\App",
        "type": "::",
        "args": [
          "OCA\\Theming\\Controller\\UserThemeController",
          "getBackground",
          {
            "__class__": "OC\\AppFramework\\DependencyInjection\\DIContainer"
          },
          [
            "theming.userTheme.getBackground"
          ]
        ]
      },
      {
        "file": "/srv/www/htdocs/server/lib/base.php",
        "line": 1047,
        "function": "match",
        "class": "OC\\Route\\Router",
        "type": "->",
        "args": [
          "/apps/theming/background"
        ]
      },
      {
        "file": "/srv/www/htdocs/server/index.php",
        "line": 36,
        "function": "handleRequest",
        "class": "OC",
        "type": "::",
        "args": []
      }
    ],
    "File": "/srv/www/htdocs/server/apps/theming/lib/Controller/UserThemeController.php",
    "Line": 76,
    "CustomMessage": "--"
  }
}

Additional info

No response

[PVince81]

how can getUser() be null ? is there an issue with the lifecycle ?

[PVince81]

I've done further tests and directly after setting the background, I see background.jpg appearing in appdata under the "theming" app

but as soon as I shift+refresh, that file disappears

maybe the migration code / cron (ajax cron on local env) is wrongly deleting the file. Ref: #34587

[PVince81]

@blizzz FYI

[PVince81]

it's not the migration job, when commented out a shift+refresh (at most 2x) will delete "background.jpg".

not sure if it's the null user or something else at play

[PVince81]

also note, I have custom theme colors set, in case it matters:

MariaDB [nextcloud]> select * from oc_appconfig where appid='theming';
+---------+-------------------+----------------------------+
| appid   | configkey         | configvalue                |
+---------+-------------------+----------------------------+
| theming | cachebuster       | 9                          |
| theming | color             | #C96C42                    |
| theming | enabled           | yes                        |
| theming | installed_version | 2.0.0                      |
| theming | slogan            | a safe dev env for my data |
| theming | types             | logging                    |
+---------+-------------------+----------------------------+

[PVince81]

it's not the "/background" endpoint, I tried refreshing it in a separate tab and background.jpg does not get deleted

maybe it's the settings page that resets it upon reload?

[PVince81]

ok, we found the issue, it has multiple layers:

1. Here we are clearing the theme's cache:

   server/apps/theming/lib/Controller/UserThemeController.php

   Line 185 in dff4f8a

   $this->themingDefaults->increaseCacheBuster();

   which in itself shouldn't be a bad thing, and Separate backend admin and user theming #34472 is for separating the cache buster part. However, see 2)

2. When clearing the admin theme, it will delete everything inside the "appdata_*/theming folder" including the user data.

3. The cache buster value and the user names are colliding inside the "theming" folder => here we need to separate the global and user theme data into separate folders "theming/global/$cacheBusterValue" and "theming/global/$userId"