[Bug]: Sharing with additionally added e-mail addresses not possible (bug 1)

[mpivchev]

⚠️ 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 OR Nextcloud Community Forum (I've searched it).
• [x] Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• [x] I agree to follow Nextcloud's Code of Conduct.

Bug description

The reason is that the MailPlugin for autocompletion adds the user results for email matches, which does not get triggered if no mail sharing provider is available. I feel the logic to serach for a user in the system address book should rather go to the UserPlugin, but that sounds like larger work Mail Plugin https://github.com/nextcloud/server/blob/master/lib/private/Collaboration/Collaborators/MailPlugin.php#L137-L147 Plugins will be used based on available share types which get passed in from the frontend https://github.com/nextcloud/server/blob/master/lib/private/Collaboration/Collaborators/Search.php#L39

Steps to reproduce

1. have the share by mail app disabled
2. user B adds an additional email address "test@example.com"
3. Limit sharing autocompletion to only work on exact matches of email
4. user A tries to share by searching for the email "test@example.com" and gets no result, would expect user B, but not found

Expected behavior

user A tries to share by searching for the email "test@example.com" and gets no result, would expect user B, but not found

Nextcloud Server version

28

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.1

Web server

Apache (supported)

Database engine version

MySQL

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

Fresh Nextcloud Server install

Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

What user-backends are you using?

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

Configuration report

List of activated Apps

Enabled:
 - activity: 2.19.0
 - announcementcenter: 6.8.1
 - bruteforcesettings: 2.7.0
 - calendar: 4.7.7
 - circles: 27.0.1
 - cloud_federation_api: 1.10.0
 - comments: 1.17.0
 - contacts: 5.5.3
 - contactsinteraction: 1.8.0
 - dav: 1.27.1
 - deck: 1.11.5
 - encryption: 2.15.0
 - external: 5.2.1
 - federatedfilesharing: 1.17.0
 - files: 1.22.0
 - files_accesscontrol: 1.17.2
 - files_automatedtagging: 1.17.0
 - files_markdown: 2.4.1
 - files_pdfviewer: 2.8.0
 - files_readmemd: 2.0.1
 - files_reminders: 1.0.0
 - files_retention: 1.16.0
 - files_rightclick: 1.6.0
 - files_sharing: 1.19.0
 - files_texteditor: 2.15.1
 - files_trashbin: 1.17.0
 - files_versions: 1.20.0
 - firstrunwizard: 2.16.0
 - groupfolders: 15.3.8
 - guests: 2.5.2
 - impersonate: 1.14.0
 - logreader: 2.12.0
 - lookup_server_connector: 1.15.0
 - notifications: 2.15.0
 - oauth2: 1.15.2
 - onlyoffice: 9.2.2
 - password_policy: 1.17.0
 - photos: 2.3.0
 - privacy: 1.11.0
 - provisioning_api: 1.17.0
 - recommendations: 1.6.0
 - related_resources: 1.2.0
 - sendent: 3.0.10
 - serverinfo: 1.17.0
 - settings: 1.9.0
 - sharelisting: 1.2.0
 - support: 1.10.1
 - systemtags: 1.17.0
 - terms_of_service: 2.3.1
 - text: 3.8.1
 - theming: 2.2.0
 - theming_customcss: 1.16.0
 - twofactor_backupcodes: 1.16.0
 - twofactor_totp: 9.0.0
 - updatenotification: 1.17.0
 - user_saml: 5.2.7
 - viewer: 2.1.0
 - workflowengine: 2.9.0
Disabled:
 - admin_audit
 - approval
 - dashboard: 7.0.0
 - email_template_example: 0.0.1
 - federation: 1.8.0
 - files_confidential
 - files_external
 - files_lock
 - globalsiteselector
 - integration_openproject
 - nextcloud_announcements: 1.7.0
 - officeonline
 - richdocuments
 - sharebymail: 1.8.0
 - survey_client: 1.6.0
 - suspicious_login
 - user_ldap
 - user_status: 1.0.1
 - weather_status: 1.0.0

Nextcloud Signing status

Nextcloud Logs

{"reqId":"nC1HGyw0IydUigp6mVJf","level":3,"time":"July 09, 2024 14:35:08","remoteAddr":"XXXX","user":"XXXXX","app":"webdav","method":"GET","url":"/remote.php/dav/files/XXXX/Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf","message":"fread(): Argument #2 ($length) must be greater than 0","userAgent":"Mozilla/5.0 (Windows) mirall/3.13.1stable-Win64 (build 20240701) (Nextcloud, windows-10.0.22631 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"27.1.11.4","exception":{"Exception":"ValueError","Message":"fread(): Argument #2 ($length) must be greater than 0","Code":0,"Trace":[{"file":"/var/www/nextcloud/3rdparty/icewind/streams/src/Wrapper.php","line":55,"function":"fread","args":[null,0]},{"file":"/var/www/nextcloud/lib/private/Files/Stream/Encryption.php","line":351,"function":"stream_read","class":"Icewind\\Streams\\Wrapper","type":"->","args":[0]},{"file":"/var/www/nextcloud/lib/private/Files/Stream/Encryption.php","line":537,"function":"stream_read_block","class":"OC\\Files\\Stream\\Encryption","type":"->","args":[0]},{"file":"/var/www/nextcloud/lib/private/Files/Stream/Encryption.php","line":299,"function":"skipHeader","class":"OC\\Files\\Stream\\Encryption","type":"->","args":[]},{"function":"stream_open","class":"OC\\Files\\Stream\\Encryption","type":"->","args":["ocencryption://","r",0,null]},{"file":"/var/www/nextcloud/lib/private/Files/Stream/Encryption.php","line":212,"function":"fopen","args":["ocencryption://","r",false,null]},{"file":"/var/www/nextcloud/lib/private/Files/Stream/Encryption.php","line":187,"function":"wrapSource","class":"OC\\Files\\Stream\\Encryption","type":"::","args":[null,null,"ocencryption","OC\\Files\\Stream\\Encryption","r"]},{"file":"/var/www/nextcloud/lib/private/Files/Storage/Wrapper/Encryption.php","line":483,"function":"wrap","class":"OC\\Files\\Stream\\Encryption","type":"::","args":[null,"files/Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf","/XXXX/files/Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf",["OC_DEFAULT_MODULE"],"XXX",["OCA\\Encryption\\Crypto\\Encryption"],["OC\\Files\\Storage\\Wrapper\\Quota",null,null,null,null,null],["OC\\Files\\Storage\\Wrapper\\Encryption",null,null,null,null,null],["OC\\Encryption\\Util"],["OC\\Encryption\\File"],"r",0,0,0,false]},{"file":"/var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php","line":307,"function":"fopen","class":"OC\\Files\\Storage\\Wrapper\\Encryption","type":"->","args":["files/Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf","r"]},{"file":"/var/www/nextcloud/apps/files_accesscontrol/lib/StorageWrapper.php","line":237,"function":"fopen","class":"OC\\Files\\Storage\\Wrapper\\Wrapper","type":"->","args":["files/Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf","r"]},{"file":"/var/www/nextcloud/apps/terms_of_service/lib/Filesystem/StorageWrapper.php","line":82,"function":"fopen","class":"OCA\\FilesAccessControl\\StorageWrapper","type":"->","args":["files/Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf","r"]},{"file":"/var/www/nextcloud/lib/private/Files/View.php","line":1165,"function":"fopen","class":"OCA\\TermsOfService\\Filesystem\\StorageWrapper","type":"->","args":["files/Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf","r"]},{"file":"/var/www/nextcloud/lib/private/Files/View.php","line":993,"function":"basicOperation","class":"OC\\Files\\View","type":"->","args":["fopen","/Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf",["read"],"r"]},{"file":"/var/www/nextcloud/apps/dav/lib/Connector/Sabre/File.php","line":492,"function":"fopen","class":"OC\\Files\\View","type":"->","args":["Promotion/Approach_Expose/Indikatorenset/Landschaft/Zwischenergebnisse/focal1m/focal1m_son/hdr.adf","r"]},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/CorePlugin.php","line":85,"function":"get","class":"OCA\\DAV\\Connector\\Sabre\\File","type":"->","args":[]},{"file":"/var/www/nextcloud/3rdparty/sabre/event/lib/WildcardEmitterTrait.php","line":89,"function":"httpGet","class":"Sabre\\DAV\\CorePlugin","type":"->","args":[["Sabre\\HTTP\\Request"],["Sabre\\HTTP\\Response"]]},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":472,"function":"emit","class":"Sabre\\DAV\\Server","type":"->","args":["method:GET",[["Sabre\\HTTP\\Request"],["Sabre\\HTTP\\Response"]]]},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":253,"function":"invokeMethod","class":"Sabre\\DAV\\Server","type":"->","args":[["Sabre\\HTTP\\Request"],["Sabre\\HTTP\\Response"]]},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":321,"function":"start","class":"Sabre\\DAV\\Server","type":"->","args":[]},{"file":"/var/www/nextcloud/apps/dav/lib/Server.php","line":371,"function":"exec","class":"Sabre\\DAV\\Server","type":"->","args":[]},{"file":"/var/www/nextcloud/apps/dav/appinfo/v2/remote.php","line":35,"function":"exec","class":"OCA\\DAV\\Server","type":"->","args":[]},{"file":"/var/www/nextcloud/remote.php","line":172,"args":["/var/www/nextcloud/apps/dav/appinfo/v2/remote.php"],"function":"require_once"}],"File":"/var/www/nextcloud/3rdparty/icewind/streams/src/Wrapper.php","Line":55,"message":"fread(): Argument #2 ($length) must be greater than 0","exception":{},"CustomMessage":"fread(): Argument #2 ($length) must be greater than 0"}}

Additional info

• The logging patch showed that listing the search results was actually canceled at the point when the current user searching was matched, which pointed to that both test users had the email in place
• After removing that email and having the "share by mail" app enabled we did get the search results as expected.