Fixes #3830 - Zammad ignores relative GitLab URLs.

lib/gitlab/http_client.rb

@@ -14,6 +14,19 @@ class GitLab
       @endpoint = endpoint
     end
 
+    # returns path of the subfolder of the endpoint if exists
+    def endpoint_path
+      path = URI.parse(endpoint).path
+      return if path.blank?
+      return if path == '/api/graphql'
+
+      if path.start_with?('/')
+        path = path[1..]
+      end
+
+      path.sub('api/graphql', '')
+    end
+
     def perform(payload)
       response = UserAgent.post(
         endpoint,

lib/gitlab/linked_issue.rb

@@ -106,6 +106,10 @@ class GitLab
       fullpath = $2
       id       = $3
 
+      if client.endpoint_path.present?
+        fullpath.sub!(client.endpoint_path, '')
+      end
+
       if client.endpoint.exclude?(host)
         raise Exceptions::UnprocessableEntity, "Issue link doesn't match configured GitLab endpoint '#{client.endpoint}'"
       end

spec/integration/gitlab_spec.rb

@@ -77,4 +77,17 @@ RSpec.describe GitLab, type: :integration, required_envs: %w[GITLAB_ENDPOINT GIT
       end
     end
   end
+
+  describe '#variables' do
+    describe 'Zammad ignores relative GitLab URLs #3830' do
+      let(:endpoint) { ENV['GITLAB_ENDPOINT'].sub('api/graphql', 'subfolder/api/graphql') }
+      let(:instance) { described_class.new(endpoint, ENV['GITLAB_APITOKEN']) }
+      let(:issue_url) { "https://#{URI.parse(ENV['GITLAB_ISSUE_LINK']).host}/subfolder/group/project/-/issues/1" }
+      let(:linked_issue) { GitLab::LinkedIssue.new(instance.client) }
+
+      it 'does remove the subfolder from the fullpath to get the issue correctly' do
+        expect(linked_issue.send(:variables, issue_url)[:fullpath]).to eq('group/project')
+      end
+    end
+  end
 end