[Bug]: occ preview:generate-all yields Malformed state response from server

### ⚠️ This issue respects the following points: ⚠️

- [x] This is a **bug**, not a question or a configuration/webserver/proxy issue.
- [x] This issue is **not** already reported on [Github](https://github.com/nextcloud/server/issues?q=is%3Aopen+is%3Aissue+label%3Abug) OR [Nextcloud Community Forum](https://help.nextcloud.com/) _(I've searched it)_.
- [x] Nextcloud Server **is** up to date. See [Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) for supported versions.
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/).

### Bug description

Hi there,

first: thanks for all your effort :).

This might be related to [#305](https://github.com/nextcloud/previewgenerator/issues/305) from the previewgenerator repository. But since the issue did not seem to have any further relevance and the advice was to post results here, I decided to post my findings here.

I was running ```occ preview:generate-all -vvv``` and at some point got an Icewind\SMB\Exception\Exception: "Malformed state response from server".

I narrowed the problem down to specific folders with a certain amount of subfolders and a certain amount of files. The check if a file ".nomedia" exists leads in those cases to the exception (none of my folders contains a ".nomedia" file). It should yield an "OCP\Files\NotFoundException". To circumvent using ```occ preview:generate-all -vvv``` every time, the following command can also be used to produce the error (I have tried to generalize the folder structure as far as possible):

```php
www-data@387d966aeb93:~/html$ php occ preview:generate-all -vvv -p /samy/files/09iMAGES/12345678/12345678/1234/12345678901234567890/123456/.nomedia
2025-12-28T12:13:55+00:00 Specifications: [{"width":64,"height":64,"crop":true},{"width":256,"height":256,"crop":true},{"width":1024,"height":1024,"crop":true},{"width":64,"height":64,"crop":false,"mode":"fill"},{"width":256,"height":256,"crop":false,"mode":"fill"},{"width":1024,"height":1024,"crop":false,"mode":"fill"},{"width":-1,"height":64,"crop":false},{"width":-1,"height":256,"crop":false},{"width":-1,"height":1024,"crop":false},{"width":64,"height":-1,"crop":false},{"width":256,"height":-1,"crop":false},{"width":1024,"height":-1,"crop":false}]
2025-12-28T12:13:55+00:00
2025-12-28T12:13:55+00:00 In Parser.php line 156:
2025-12-28T12:13:55+00:00
2025-12-28T12:13:55+00:00   [Icewind\SMB\Exception\Exception]
2025-12-28T12:13:55+00:00   Malformed state response from server
2025-12-28T12:13:55+00:00
2025-12-28T12:13:55+00:00
2025-12-28T12:13:55+00:00 Exception trace:
2025-12-28T12:13:55+00:00   at /var/www/html/3rdparty/icewind/smb/src/Wrapped/Parser.php:156
2025-12-28T12:13:55+00:00  Icewind\SMB\Wrapped\Parser->parseStat() at /var/www/html/3rdparty/icewind/smb/src/Wrapped/Share.php:216
2025-12-28T12:13:55+00:00  Icewind\SMB\Wrapped\Share->stat() at /var/www/html/apps/files_external/lib/Lib/Storage/SMB.php:169
2025-12-28T12:13:55+00:00  OCA\Files_External\Lib\Storage\SMB->getFileInfo() at /var/www/html/apps/files_external/lib/Lib/Storage/SMB.php:645
2025-12-28T12:13:55+00:00  OCA\Files_External\Lib\Storage\SMB->file_exists() at /var/www/html/lib/private/Files/Storage/Wrapper/Wrapper.php:115
2025-12-28T12:13:55+00:00  OC\Files\Storage\Wrapper\Wrapper->file_exists() at /var/www/html/lib/private/Files/Storage/Wrapper/Wrapper.php:115
2025-12-28T12:13:55+00:00  OC\Files\Storage\Wrapper\Wrapper->file_exists() at n/a:n/a
2025-12-28T12:13:55+00:00  call_user_func_array() at /var/www/html/lib/private/Files/Storage/Wrapper/Availability.php:83
2025-12-28T12:13:55+00:00  OC\Files\Storage\Wrapper\Availability->handleAvailability() at /var/www/html/lib/private/Files/Storage/Wrapper/Availability.php:150
2025-12-28T12:13:55+00:00  OC\Files\Storage\Wrapper\Availability->file_exists() at /var/www/html/lib/private/Files/Storage/Wrapper/Wrapper.php:115
2025-12-28T12:13:55+00:00  OC\Files\Storage\Wrapper\Wrapper->file_exists() at /var/www/html/lib/private/Files/View.php:1383
2025-12-28T12:13:55+00:00  OC\Files\View->getCacheEntry() at /var/www/html/lib/private/Files/View.php:1424
2025-12-28T12:13:55+00:00  OC\Files\View->getFileInfo() at /var/www/html/lib/private/Files/Node/Root.php:178
2025-12-28T12:13:55+00:00  OC\Files\Node\Root->get() at /var/www/html/lib/private/Files/Node/Folder.php:108
2025-12-28T12:13:55+00:00  OC\Files\Node\Folder->get() at /var/www/html/custom_apps/previewgenerator/lib/Command/Generate.php:235
2025-12-28T12:13:55+00:00  OCA\PreviewGenerator\Command\Generate->generatePathPreviews() at /var/www/html/custom_apps/previewgenerator/lib/Command/Generate.php:185
2025-12-28T12:13:55+00:00  OCA\PreviewGenerator\Command\Generate->executeDefault() at /var/www/html/custom_apps/previewgenerator/lib/Command/Generate.php:124
2025-12-28T12:13:55+00:00  OCA\PreviewGenerator\Command\Generate->execute() at /var/www/html/3rdparty/symfony/console/Command/Command.php:326
2025-12-28T12:13:55+00:00  Symfony\Component\Console\Command\Command->run() at /var/www/html/3rdparty/symfony/console/Application.php:1078
2025-12-28T12:13:55+00:00  Symfony\Component\Console\Application->doRunCommand() at /var/www/html/3rdparty/symfony/console/Application.php:324
2025-12-28T12:13:55+00:00  Symfony\Component\Console\Application->doRun() at /var/www/html/3rdparty/symfony/console/Application.php:175
2025-12-28T12:13:55+00:00  Symfony\Component\Console\Application->run() at /var/www/html/lib/private/Console/Application.php:187
2025-12-28T12:13:55+00:00  OC\Console\Application->run() at /var/www/html/console.php:90
2025-12-28T12:13:55+00:00  require_once() at /var/www/html/occ:33
2025-12-28T12:13:55+00:00
2025-12-28T12:13:55+00:00 preview:generate-all [-p|--path [PATH]] [-w|--workers [WORKERS]] [--] [<user_id>...]
2025-12-28T12:13:55+00:00
``` 

The last folder "123456" contains exactly 51 files. If I remove one file, it works:

```php
www-data@387d966aeb93:~/html$ php occ preview:generate-all -vvv -p /samy/files/09iMAGES/12345678/12345678/1234/12345678901234567890/123456/.nomedia
2025-12-28T12:22:14+00:00 Specifications: [{"width":64,"height":64,"crop":true},{"width":256,"height":256,"crop":true},{"width":1024,"height":1024,"crop":true},{"width":64,"height":64,"crop":false,"mode":"fill"},{"width":256,"height":256,"crop":false,"mode":"fill"},{"width":1024,"height":1024,"crop":false,"mode":"fill"},{"width":-1,"height":64,"crop":false},{"width":-1,"height":256,"crop":false},{"width":-1,"height":1024,"crop":false},{"width":64,"height":-1,"crop":false},{"width":256,"height":-1,"crop":false},{"width":1024,"height":-1,"crop":false}]
2025-12-28T12:22:15+00:00
2025-12-28T12:22:15+00:00 In Root.php line 182:
2025-12-28T12:22:15+00:00
2025-12-28T12:22:15+00:00   [OCP\Files\NotFoundException]
2025-12-28T12:22:15+00:00   /samy/files/09iMAGES/12345678/12345678/1234/12345678901234567890/123456/.nomedia
2025-12-28T12:22:15+00:00
2025-12-28T12:22:15+00:00
2025-12-28T12:22:15+00:00 Exception trace:
2025-12-28T12:22:15+00:00   at /var/www/html/lib/private/Files/Node/Root.php:182
2025-12-28T12:22:15+00:00  OC\Files\Node\Root->get() at /var/www/html/lib/private/Files/Node/Folder.php:108
2025-12-28T12:22:15+00:00  OC\Files\Node\Folder->get() at /var/www/html/custom_apps/previewgenerator/lib/Command/Generate.php:235
2025-12-28T12:22:15+00:00  OCA\PreviewGenerator\Command\Generate->generatePathPreviews() at /var/www/html/custom_apps/previewgenerator/lib/Command/Generate.php:185
2025-12-28T12:22:15+00:00  OCA\PreviewGenerator\Command\Generate->executeDefault() at /var/www/html/custom_apps/previewgenerator/lib/Command/Generate.php:124
2025-12-28T12:22:15+00:00  OCA\PreviewGenerator\Command\Generate->execute() at /var/www/html/3rdparty/symfony/console/Command/Command.php:326
2025-12-28T12:22:15+00:00  Symfony\Component\Console\Command\Command->run() at /var/www/html/3rdparty/symfony/console/Application.php:1078
2025-12-28T12:22:15+00:00  Symfony\Component\Console\Application->doRunCommand() at /var/www/html/3rdparty/symfony/console/Application.php:324
2025-12-28T12:22:15+00:00  Symfony\Component\Console\Application->doRun() at /var/www/html/3rdparty/symfony/console/Application.php:175
2025-12-28T12:22:15+00:00  Symfony\Component\Console\Application->run() at /var/www/html/lib/private/Console/Application.php:187
2025-12-28T12:22:15+00:00  OC\Console\Application->run() at /var/www/html/console.php:90
2025-12-28T12:22:15+00:00  require_once() at /var/www/html/occ:33
2025-12-28T12:22:15+00:00
2025-12-28T12:22:15+00:00 preview:generate-all [-p|--path [PATH]] [-w|--workers [WORKERS]] [--] [<user_id>...]
2025-12-28T12:22:15+00:00
```

It also works if any of the folder names is one character shorter, e.g.:

```php occ preview:generate-all -vvv -p /samy/files/09iMAGES/12345678/12345678/1234/12345678901234567890/12345/.nomedia```

or if calling it on a folder without content (234567)

```php occ preview:generate-all -vvv -p /samy/files/09iMAGES/12345678/12345678/1234/12345678901234567890/234567/.nomedia```.


I could narrow this down to the ```Icewind\SMB\Wrapped::stat``` function and more precisely the therein called ```Icewind\SMB\Wrapped::dir``` function and even more precisely the therein called ```$output = $this->execute('dir')```.

I have tried to manually reconstruct what is happening in the ```smbclient``` tool, but even with the provided environment variables for the ```proc_open``` command in the ```RawConnection.php``` I do not succeed in producing a faulty behavior of ```smbclient```. What I could debug so far is that the ```Icewdind\SMB\Wrapped\Connection::read``` function does not return the prompt "smb:" after  calling ```$this->execute('cd /')``` in ```Icewind\SMB\Wrapped::dir```, which it does return for working paths. Also, I could see that  the responses from calls to ```smbclient``` seem to be delayed by "one call". Meaning that after calling the dir command, for subsequent commands the corresponding response is read only after the next call which leads to the problem - in my opinion.

However, when exchanging the call ```$output = $this->execute('dir')``` with ```$output = $this->execute('dir ' . substr($escapedPath, 0, -1).'\*"');``` and thus making it an explicit dir call on the content of the path, everything works. So this would be a solution, but I do not know what is actually breaking after the normal dir call.

While writing this I notice that the issue is likely with the 3rdparty library. If this issue would be better placed there I will be glad to post it there. I was just following the lead from the issue that I found to be similar to this one.

Thanks

Samy



### Steps to reproduce

1. Login to the docker container as user www-data using docker exec -itu www-data container_id /bin/bash
2. Call php occ preview:generate-all -vvv -p /samy/files/09iMAGES/12345678/12345678/1234/12345678901234567890/123456/.nomedia (the file ".nomedia" should not exist)



### Expected behavior

Should return an ```OCP\Files\NotFoundException```.

### Nextcloud Server version

32

### Operating system

Debian/Ubuntu in a docker container

### PHP engine version

PHP 8.3

### Web server

Apache (supported)

### Database engine version

MariaDB

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

None

### Are you using the Nextcloud Server Encryption module?

None

### What user-backends are you using?

- [x] Default user-backend _(database)_
- [ ] LDAP/ Active Directory
- [ ] SSO - SAML
- [ ] Other

### Configuration report

```json
{
    "system": {
        "htaccess.RewriteBase": "\/",
        "memcache.local": "\\OC\\Memcache\\APCu",
        "filelocking.enabled": true,
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "upgrade.disable-web": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "*",
            "*",
            "*"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "32.0.3.2",
        "overwrite.cli.url": "***REMOVED SENSITIVE VALUE***",
        "overwriteprotocol": "https",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "maintenance": false,
        "loglevel": 3,
        "maintenance_window_start": "1",
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "default_phone_region": "DE",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "enabledPreviewProviders": [
            "OC\\Preview\\Imaginary"
        ],
        "preview_imaginary_url": "***REMOVED SENSITIVE VALUE***",
        "preview_max_x": 1024,
        "preview_max_y": 1024
    }
}
```

### List of activated Apps

```shell
Enabled:
  - activity: 5.0.0-dev.0
  - bruteforcesettings: 5.0.0-dev.0
  - calendar: 6.1.2
  - circles: 32.0.0
  - cloud_federation_api: 1.16.0
  - contacts: 8.1.2
  - contactsinteraction: 1.13.1
  - dashboard: 7.12.0
  - dav: 1.34.2
  - federatedfilesharing: 1.22.0
  - files: 2.4.0
  - files_downloadlimit: 5.0.0-dev.0
  - files_external: 1.24.0
  - files_pdfviewer: 5.0.0-dev.0
  - files_reminders: 1.5.0
  - files_sharing: 1.24.1
  - files_trashbin: 1.22.0
  - files_versions: 1.25.0
  - logreader: 5.0.0-dev.0
  - lookup_server_connector: 1.20.0
  - nextcloud_announcements: 4.0.0-dev.0
  - notifications: 5.0.0-dev.0
  - oauth2: 1.20.0
  - password_policy: 4.0.0-dev.0
  - passwords: 2025.12.21
  - photos: 5.0.0-dev.1
  - previewgenerator: 5.11.0
  - privacy: 4.0.0-dev.0
  - profile: 1.1.0
  - provisioning_api: 1.22.0
  - recommendations: 5.0.0-dev.0
  - related_resources: 3.0.0-dev.0
  - serverinfo: 4.0.0-dev.0
  - settings: 1.15.1
  - sharebymail: 1.22.0
  - support: 4.0.0-dev.0
  - text: 6.0.1
  - theming: 2.7.0
  - twofactor_backupcodes: 1.21.0
  - updatenotification: 1.22.0
  - user_status: 1.12.0
  - viewer: 5.0.0-dev.0
  - weather_status: 1.12.0
  - webhook_listeners: 1.3.0
  - workflowengine: 2.14.0
Disabled:
  - admin_audit: 1.22.0
  - app_api: 32.0.0 (installed 4.0.6)
  - comments: 1.22.0 (installed 1.20.1)
  - encryption: 2.20.0
  - federation: 1.22.0 (installed 1.20.0)
  - firstrunwizard: 5.0.0-dev.0 (installed 3.0.0)
  - survey_client: 4.0.0-dev.0 (installed 2.0.0)
  - suspicious_login: 10.0.0-dev.0
  - systemtags: 1.22.0 (installed 1.20.0)
  - twofactor_nextcloud_notification: 6.0.0-dev.0
  - twofactor_totp: 14.0.0
  - user_ldap: 1.23.0
```

### Nextcloud Signing status

```shell
No errors have been found.
```

### Nextcloud Logs

```json

```

### Additional info

_No response_

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Uh oh!

[Bug]: occ preview:generate-all yields Malformed state response from server #57275

⚠️ This issue respects the following points: ⚠️

Bug description

Steps to reproduce

Expected behavior

Nextcloud Server version

Operating system

PHP engine version

Web server

Database engine version

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

Are you using the Nextcloud Server Encryption module?

What user-backends are you using?

Configuration report

List of activated Apps

Nextcloud Signing status

Nextcloud Logs

Additional info

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Uh oh!

[Bug]: occ preview:generate-all yields Malformed state response from server #57275

Description

⚠️ This issue respects the following points: ⚠️

Bug description

Steps to reproduce

Expected behavior

Nextcloud Server version

Operating system

PHP engine version

Web server

Database engine version

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

Are you using the Nextcloud Server Encryption module?

What user-backends are you using?

Configuration report

List of activated Apps

Nextcloud Signing status

Nextcloud Logs

Additional info

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions