<!--- Please read this! Before opening a new issue, make sure to search for keywords in the issues filtered by the "regression" or "bug" label: - https://gitlab.com/gitlab-org/gitlab/issues?label_name%5B%5D=regression - https://gitlab.com/gitlab-org/gitlab/issues?label_name%5B%5D=bug and verify the issue you're about to submit isn't a duplicate. ---> ### Summary Since GitLab 13.0 relative wiki URLs point to the wrong place if an external_url with a non-empty prefix / contextPath is used. In relative wiki URLs the context path will be duplicated. If https://dev.reset.inso-w.at/repo is the external_url, a project 'asdf' inside a group 'asdf' exists, then a relative wiki URL `[[otherpage]]` will point to https://dev.reset.inso-w.at/repo/repo/asdf/asdf/-/wikis/otherpage while it should point to https://dev.reset.inso-w.at/repo/asdf/asdf/-/wikis/otherpage for example. The `/repo` part is duplicated. ### Steps to reproduce The following docker-compose config will reproduce the behaviour. ``` version: "3.3" services: gitlab: image: gitlab/gitlab-ce:13.0.0-ce.0 environment: GITLAB_OMNIBUS_CONFIG: | external_url 'https://example.com/repo' ``` The /repo part is crucial. Create a wiki page and use the `[[otherpage]]` syntax to link to another page. ### Example Project Not applicable, since gitlab.com is not affected. ### What is the current *bug* behavior? Wrong link with duplicated contextPath. ### What is the expected *correct* behavior? Links should not duplicate the contextPath. ### Relevant logs and/or screenshots  ### Output of checks No, this does not happen on GitLab.com. #### Results of GitLab environment info ``` # gitlab-rake gitlab:env:info System information System: Current User: git Using RVM: no Ruby Version: 2.6.6p146 Gem Version: 2.7.10 Bundler Version:1.17.3 Rake Version: 12.3.3 Redis Version: 5.0.9 Git Version: 2.26.2 Sidekiq Version:5.2.7 Go Version: unknown GitLab information Version: 13.0.0 Revision: 6743e883eae Directory: /opt/gitlab/embedded/service/gitlab-rails DB Adapter: PostgreSQL DB Version: 11.7 URL: http://dev.reset.inso-w.at/repo HTTP Clone URL: http://dev.reset.inso-w.at/repo/some-group/some-project.git SSH Clone URL: git@dev.reset.inso-w.at:some-group/some-project.git Using LDAP: no Using Omniauth: yes Omniauth Providers: GitLab Shell Version: 13.2.0 Repository storage paths: - default: /var/opt/gitlab/git-data/repositories GitLab Shell path: /opt/gitlab/embedded/service/gitlab-shell Git: /opt/gitlab/embedded/bin/git ``` #### Results of GitLab application Check <details> <summary>Expand for output related to the GitLab application check</summary> <pre> ``` # gitlab-rake gitlab:check SANITIZE=true Checking GitLab subtasks ... Checking GitLab Shell ... GitLab Shell: ... GitLab Shell version >= 13.2.0 ? ... OK (13.2.0) Running /opt/gitlab/embedded/service/gitlab-shell/bin/check Internal API available: OK Redis available via internal API: OK gitlab-shell self-check successful Checking GitLab Shell ... Finished Checking Gitaly ... Gitaly: ... default ... OK Checking Gitaly ... Finished Checking Sidekiq ... Sidekiq: ... Running? ... yes Number of Sidekiq processes ... 1 Checking Sidekiq ... Finished Checking Incoming Email ... Incoming Email: ... Reply by email is disabled in config/gitlab.yml Checking Incoming Email ... Finished Checking LDAP ... LDAP: ... LDAP is disabled in config/gitlab.yml Checking LDAP ... Finished Checking GitLab App ... Git configured correctly? ... yes Database config exists? ... yes All migrations up? ... yes Database contains orphaned GroupMembers? ... no GitLab config exists? ... yes GitLab config up to date? ... yes Log directory writable? ... yes Tmp directory writable? ... yes Uploads directory exists? ... yes Uploads directory has correct permissions? ... yes Uploads directory tmp has correct permissions? ... skipped (no tmp uploads folder yet) Init script exists? ... skipped (omnibus-gitlab has no init script) Init script up-to-date? ... skipped (omnibus-gitlab has no init script) Projects have namespace: ... 3/1 ... yes Redis version >= 4.0.0? ... yes Ruby version >= 2.5.3 ? ... yes (2.6.6) Git version >= 2.22.0 ? ... yes (2.26.2) Git user has default SSH configuration? ... yes Active users: ... 2 Is authorized keys file accessible? ... yes GitLab configured to store new projects in hashed storage? ... yes All projects are in hashed storage? ... yes Checking GitLab App ... Finished Checking GitLab subtasks ... Finished ``` </pre> </details> ### Possible fixes (If you can, link to the line of code that might be responsible for the problem)