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 🤭