Merge branch 'kassio/fix-ci-build-pages-path-prefix-expansion' into 'master'

Fix pages path_prefix ci variable expansion

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/138593



Merged-by: Allison Browne <abrowne@gitlab.com>
Approved-by: Thomas Hutterer <thutterer@gitlab.com>
Approved-by: Allison Browne <abrowne@gitlab.com>
Co-authored-by: Kassio Borges <kassioborgesm@gmail.com>

ee/app/models/ee/ci/build.rb

@@ -223,7 +223,7 @@ def pages
 
         (options&.dig(:pages) || {}).tap do |pages_options|
           if ::Gitlab::Pages.multiple_versions_enabled_for?(project)
-            pages_options[:path_prefix] = ExpandVariables.expand(pages_options[:path_prefix], -> {
+            pages_options[:path_prefix] = ExpandVariables.expand(pages_options[:path_prefix].to_s, -> {
               variables.sort_and_expand_all
             })
           else

ee/spec/models/ci/build_spec.rb

@@ -985,6 +985,7 @@
       false | false | { pages: { path_prefix: 'foo' } } | {}
       false | true | { pages: { path_prefix: 'foo' } } | {}
       true | false | { pages: { path_prefix: 'foo' } } | {}
+      true | true | { pages: { path_prefix: nil } } | { path_prefix: '' }
       true | true | { pages: { path_prefix: 'foo' } } | { path_prefix: 'foo' }
       true | true | { pages: { path_prefix: '$CI_COMMIT_BRANCH' } } | { path_prefix: 'master' }
     end