Fix logger overwriting vars in some circumstances

[blizzz]

We were investigating one case, indicated by the error foreach() argument must be of type array|object, string given

This can be reproduce like this:

1.) in php.ini, zend.exception_ignore_args is set to "Off" (PHP default, check distro in doubt)
2.) app files_lock enabled
3.) use an addressbook client (like KAddressbook)
4.) there, add a new contact

You will see an exception like:

{
  "Exception": "Error",
  "Message": "Invalid argument supplied for foreach() at /srv/http/nextcloud/stable24/3rdparty/sabre/dav/lib/DAV/Server.php#1454",
  "Code": 0,
  "Trace": [
    {
      "file": "/srv/http/nextcloud/stable24/3rdparty/sabre/dav/lib/DAV/Server.php",
      "line": 1454,
      "function": "onAll",
      "class": "OC\\Log\\ErrorHandler",
      "type": "::",
      "args": [
        2,
        "Invalid argument supplied for foreach()",
        "/srv/http/nextcloud/stable24/3rdparty/sabre/dav/lib/DAV/Server.php",
        1454,
        {
          "request": {
            "__class__": "Sabre\\HTTP\\Request"
          },
          "response": {
            "__class__": "Sabre\\HTTP\\Response"
          },
          "path": "addressbooks/users/stable24/contacts/1655379707.R254.vcf",
          "node": null,
          "lastMod": null,
          "etag": null,
          "ifMatch": null,
          "e": {
            "__class__": "Sabre\\DAV\\Exception\\NotFound"
          },
          "ifNoneMatch": "*",
          "nodeExists": false,
          "ifUnmodifiedSince": null,
          "ifConditions": "*** sensitive parameter replaced ***"
        }
      ]
    },
    {
      "file": "/srv/http/nextcloud/stable24/3rdparty/sabre/dav/lib/DAV/Server.php",
      "line": 466,
      "function": "checkPreconditions",
      "class": "Sabre\\DAV\\Server",
      "type": "->",
      "args": [
        {
          "__class__": "Sabre\\HTTP\\Request"
        },
        {
          "__class__": "Sabre\\HTTP\\Response"
        }
      ]
    },
    {
      "file": "/srv/http/nextcloud/stable24/3rdparty/sabre/dav/lib/DAV/Server.php",
      "line": 253,
      "function": "invokeMethod",
      "class": "Sabre\\DAV\\Server",
      "type": "->",
      "args": [
        {
          "__class__": "Sabre\\HTTP\\Request"
        },
        {
          "__class__": "Sabre\\HTTP\\Response"
        }
      ]
    },
    {
      "file": "/srv/http/nextcloud/stable24/3rdparty/sabre/dav/lib/DAV/Server.php",
      "line": 321,
      "function": "start",
      "class": "Sabre\\DAV\\Server",
      "type": "->",
      "args": []
    },
    {
      "file": "/srv/http/nextcloud/stable24/apps/dav/lib/Server.php",
      "line": 352,
      "function": "exec",
      "class": "Sabre\\DAV\\Server",
      "type": "->",
      "args": []
    },
    {
      "file": "/srv/http/nextcloud/stable24/apps/dav/appinfo/v2/remote.php",
      "line": 35,
      "function": "exec",
      "class": "OCA\\DAV\\Server",
      "type": "->",
      "args": []
    },
    {
      "file": "/srv/http/nextcloud/stable24/remote.php",
      "line": 166,
      "args": [
        "/srv/http/nextcloud/stable24/apps/dav/appinfo/v2/remote.php"
      ],
      "function": "require_once"
    }
  ],
  "File": "/srv/http/nextcloud/stable24/lib/private/Log/ErrorHandler.php",
  "Line": 99,
  "CustomMessage": "--"
}

The hidden issue is that a variable, passed by reference, was overwritten. I used to be an array and was turned into a string *** sensitive parameter replaced ***.

Now we have a test to reproduce the issue and the fix.

This problem popped up in a related scenario, where we committed a temporary fix: #32685

[blizzz]

/backport to stable25

[blizzz]

/backport to stable24

[blizzz]

/backport to stable23

[blizzz]

special thanks to @miaulalala and @mgallien for the debugging sessions <3

[come-nc]

Nasty one

[skjnldsv]

nice!

[backportbot-nextcloud]

The backport to stable25 failed. Please do this backport manually.

[blizzz]

/backport to stable22

[blizzz]

The backport to stable25 failed. Please do this backport manually.

off by one 🤭