SVG logo URL embedded in emails return SVG content, despite useSvg=0

[agross]

The logo I uploaded to Nextcloud via the Theming section is returned as SVG. The URL embedded in the mail template is: https://cloud.grossweber.com/apps/theming/image/logo?useSvg=0&v=21

$ curl 'https://cloud.grossweber.com/apps/theming/image/logo?useSvg=0&v=21'
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 303.11 59.689">...

Steps to reproduce

1. Add SVG logo via Theming
2. Send email (Activity Notification in my case)
3. Open in Gmail or Spark (in my case)

Expected behaviour

Logo should be displayed

Actual behaviour

I get the broken image placeholder

Server configuration

Operating system: Linux/docker

Web server: nginx

Database: MariaDB

PHP version: 7.2.14

Nextcloud version: 15.0.2

Updated from an older Nextcloud/ownCloud or fresh install: oC 10 -> NC 12, 13, 14, 15. After that to logo was added.

Where did you install Nextcloud from: docker

List of activated apps:

App list

Enabled:
  - accessibility: 1.1.0
  - activity: 2.8.2
  - admin_audit: 1.5.0
  - bruteforcesettings: 1.3.0
  - camerarawpreviews: 0.6.3
  - checksum: 0.4.2
  - cloud_federation_api: 0.1.0
  - comments: 1.5.0
  - dav: 1.8.1
  - federatedfilesharing: 1.5.0
  - federation: 1.5.0
  - files: 1.10.0
  - files_external: 1.6.0
  - files_fulltextsearch: 1.2.3
  - files_pdfviewer: 1.4.0
  - files_rightclick: 0.11.0
  - files_sharing: 1.7.0
  - files_texteditor: 2.7.0
  - files_trashbin: 1.5.0
  - files_versions: 1.8.0
  - files_videoplayer: 1.4.0
  - firstrunwizard: 2.4.0
  - fulltextsearch: 1.2.3
  - fulltextsearch_elasticsearch: 1.2.2
  - gallery: 18.2.0
  - impersonate: 1.2.0
  - logreader: 2.0.0
  - lookup_server_connector: 1.3.0
  - nextcloud_announcements: 1.4.0
  - notifications: 2.3.0
  - oauth2: 1.3.0
  - password_policy: 1.5.0
  - provisioning_api: 1.5.0
  - serverinfo: 1.5.0
  - sharebymail: 1.5.0
  - support: 1.0.0
  - survey_client: 1.3.0
  - systemtags: 1.5.0
  - theming: 1.6.0
  - twofactor_backupcodes: 1.4.1
  - twofactor_totp: 2.1.0
  - updatenotification: 1.5.0
  - workflowengine: 1.5.0
Disabled:
  - encryption
  - user_ldap

Nextcloud configuration:

Config report

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "version": "15.0.2.0",
        "installed": true,
        "maintenance": false,
        "singleuser": false,
        "htaccess.RewriteBase": "\/",
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "dbtype": "mysql",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "owncloud.home.therightstuff.de",
            "cloud.grossweber.com"
        ],
        "overwrite.cli.url": "https:\/\/owncloud.home.therightstuff.de",
        "loglevel": 2,
        "logtimezone": "Europe\/Berlin",
        "log_rotate_size": 10485760,
        "log_rotate_sizerotation": 3,
        "mail_smtpmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpsecure": "tls",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpauth": 1,
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "skeletondirectory": "",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 6379,
            "password": "***REMOVED SENSITIVE VALUE***"
        },
        "trashbin_retention_obligation": "auto, 30",
        "versions_retention_obligation": "auto, 3",
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "data-fingerprint": "68bc4c4bc6106a1c8c88e19ad0230ab7"
    }
}

Are you using external storage, if yes which one: No

Are you using encryption: No

Are you using an external user-backend, if yes which one: No

Logs

Web server log

Web server log

"GET /apps/theming/image/logo?useSvg=0&v=21 HTTP/1.1" 200 10336 "-" "Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko Firefox/11.0 (via ggpht.com GoogleImageProxy)"

Nextcloud log (data/nextcloud.log)

Nextcloud log

Nothing of relevance

[kesselb]

Is the ImageMagick extension installed and enabled? If not the conversion is not possible.

[agross]

@danielkesselberg Which extension? An app?

[kesselb]

ImageMagick is a extension for php similar to GD but with support for SVG. If you are using the nextcloud/docke image this extension should be present (https://github.com/nextcloud/docker/blob/250802c70679b72457e1b85f301e1a503517f780/15.0/apache/Dockerfile#L65).

Do you see the notice above?

[agross]

The docker container is based on nextcloud:apache. The notice above is displayed, but not highlighted, so I missed it. What needs to be done to enable the extension?

[kesselb]

Ah. ImageMagick is included but without svg support. nextcloud/docker#594 should do the trick. I'm closing this here.

[agross]

I installed libmagickcore-6.q16-3-extra and I also get a favicon based on the logo (which is unreadable, BTW). But when requesting https://cloud.grossweber.com/apps/theming/image/logo?useSvg=0&v=24 I still get SVG contents.

[fuse314]

I don't know if libmagickcore*-extra must be added before compiling imagemagick.
You can see the supported formats by imagemagick in phpinfo() ( search for ImageMagick supported formats ). It should display the SVG type there...

[kesselb]

I don't know if libmagickcore*-extra must be added before compiling imagemagick.

Yes. A custom dockerfile is the way to go. There are concerns about the security of ImageMagick #13099. I understand this is a bit frustrating for new users 😞

[agross]

I don't know if libmagickcore*-extra must be added before compiling imagemagick.

I added libmagickcore*-extra via apt in a custom Dockerfile. ImageMagick was already installed via nextcloud:apache (my base image).

I noticed a slight change in UI after adding the libmagickcore*-extra package which seems to be related to the SVG support being present. The favicon changes depending on the app I'm using:

• When I browse Files, I see the Files app icon (a folder) instead of Nextcoud's favicon (three circles),
• for Activity I see the bolt icon
• etc.

From my perspective Nextcloud's image handling capabilities have been extended after adding the package via apt, without requiring to actually compile ImageMagick again.

[kesselb]

$ curl -I "https://cloud.grossweber.com/apps/theming/image/logo?useSvg=0&v=24"
HTTP/2 200 
content-type: image/png
content-length: 10336

[agross]

$ curl  "https://cloud.grossweber.com/apps/theming/image/logo?useSvg=0&v=24"
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 303.11 59.689"><path fill="#ffffff"
...

Correct Content-Type, but contents are SVG.

[kesselb]

@juliushaertl 🤔