Populate description from finding if needed

ee/app/presenters/vulnerability_presenter.rb

@@ -52,6 +52,10 @@ class VulnerabilityPresenter < Gitlab::View::Presenter::Delegated
     )
   end
 
+  def description
+    vulnerability.description || finding.description
+  end
+
   private
 
   def location_link_for(path)

ee/changelogs/unreleased/284473-issues-created-from-vulnerabilities-detail-page-missing-informa.yml

+---
+title: Properly populate descriptions in an issue created from a vulnerability
+merge_request: 52592
+author:
+type: fixed

ee/spec/presenters/vulnerability_presenter_spec.rb

@@ -9,7 +9,7 @@ RSpec.describe VulnerabilityPresenter do
     { type: 'sast', status: 'success', start_time: 'placeholder', end_time: 'placeholder' }
   end
 
-  let_it_be(:finding) { create(:vulnerabilities_finding, :with_secret_detection, pipelines: [pipeline], project: project) }
+  let_it_be(:finding) { create(:vulnerabilities_finding, :with_secret_detection, pipelines: [pipeline], project: project, description: 'Finding Description') }
   let_it_be(:finding2) { create(:vulnerabilities_finding, :with_secret_detection, scan: sast_scan) }
 
   subject  { described_class.new(finding.vulnerability) }
@@ -127,4 +127,26 @@ RSpec.describe VulnerabilityPresenter do
       expect(jira_issue_description).to eq(expected_jira_issue_description)
     end
   end
+
+  describe '#description' do
+    let(:vulnerability) { finding.vulnerability }
+
+    context 'when the vulnerability description field is populated' do
+      it 'returns the description for the vulnerability' do
+        expect(subject.description).to eq(vulnerability.description)
+      end
+    end
+
+    context 'when the vulnerability description field is empty' do
+      before do
+        vulnerability.description = nil
+        vulnerability.save!
+      end
+
+      it 'returns the description for the vulnerability finding' do
+        expect(subject.description).not_to eq(vulnerability.description)
+        expect(subject.description).to eq(finding.description)
+      end
+    end
+  end
 end