Fix moving issues API failing when text includes commit URLs

When a issue is moved from one project to another, all associated
Markdown text is rewritten in the context of the new project. If the
note contained a link to a commit URL, `CommitRewriter#rewrite` would
fail because `Commit#link_reference_pattern` would match `nil` `commit`
values in the HTML generated from the Markdown. These `nil` values were
passed along to `Project#commits_by` because `Commit#reference_valid?`
was always returning `true`.

To prevent this issue from happening, we tighten up the check for
`Commit#reference_valid?` to look for valid SHA values.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/66666

1 files changed, 17 insertions, 0 deletions

diff --git a/spec/lib/gitlab/gfm/reference_rewriter_spec.rb b/spec/lib/gitlab/gfm/reference_rewriter_spec.rb
index 4d2f08f95fc..790b0428d19 100644
--- a/spec/lib/gitlab/gfm/reference_rewriter_spec.rb
+++ b/spec/lib/gitlab/gfm/reference_rewriter_spec.rb
@@ -102,6 +102,23 @@ describe Gitlab::Gfm::ReferenceRewriter do
       end
     end
 
+    context 'with a commit' do
+      let(:old_project) { create(:project, :repository, name: 'old-project', group: group) }
+      let(:commit) { old_project.commit }
+
+      context 'reference to an absolute URL to a commit' do
+        let(:text) { Gitlab::UrlBuilder.build(commit) }
+
+        it { is_expected.to eq(text) }
+      end
+
+      context 'reference to a commit' do
+        let(:text) { commit.id }
+
+        it { is_expected.to eq("#{old_project_ref}@#{text}") }
+      end
+    end
+
     context 'reference contains project milestone' do
       let!(:milestone) do
         create(:milestone, title: '9.0', project: old_project)