Merge branch 'fix-issues-api-list-performance' into 'master'

Fail when issuable_meta_data is called on an unlimited collection

Closes #39845

See merge request gitlab-org/gitlab-ce!15249

2 files changed, 14 insertions, 6 deletions

diff --git a/lib/api/issues.rb b/lib/api/issues.rb
index 0df41dcc903..74dfd9f96de 100644
--- a/lib/api/issues.rb
+++ b/lib/api/issues.rb
@@ -68,7 +68,7 @@ module API
                          desc: 'Return issues for the given scope: `created-by-me`, `assigned-to-me` or `all`'
       end
       get do
-        issues = find_issues
+        issues = paginate(find_issues)
 
         options = {
           with: Entities::IssueBasic,
@@ -76,7 +76,7 @@ module API
           issuable_metadata: issuable_meta_data(issues, 'Issue')
         }
 
-        present paginate(issues), options
+        present issues, options
       end
     end
 
@@ -95,7 +95,7 @@ module API
       get ":id/issues" do
         group = find_group!(params[:id])
 
-        issues = find_issues(group_id: group.id)
+        issues = paginate(find_issues(group_id: group.id))
 
         options = {
           with: Entities::IssueBasic,
@@ -103,7 +103,7 @@ module API
           issuable_metadata: issuable_meta_data(issues, 'Issue')
         }
 
-        present paginate(issues), options
+        present issues, options
       end
     end
 
@@ -124,7 +124,7 @@ module API
       get ":id/issues" do
         project = find_project!(params[:id])
 
-        issues = find_issues(project_id: project.id)
+        issues = paginate(find_issues(project_id: project.id))
 
         options = {
           with: Entities::IssueBasic,
@@ -133,7 +133,7 @@ module API
           issuable_metadata: issuable_meta_data(issues, 'Issue')
         }
 
-        present paginate(issues), options
+        present issues, options
       end
 
       desc 'Get a single project issue' do
diff --git a/lib/gitlab/issuable_metadata.rb b/lib/gitlab/issuable_metadata.rb
index 977c05910d3..0c9de72329c 100644
--- a/lib/gitlab/issuable_metadata.rb
+++ b/lib/gitlab/issuable_metadata.rb
@@ -1,6 +1,14 @@
 module Gitlab
   module IssuableMetadata
     def issuable_meta_data(issuable_collection, collection_type)
+      # ActiveRecord uses Object#extend for null relations.
+      if !(issuable_collection.singleton_class < ActiveRecord::NullRelation) &&
+          issuable_collection.respond_to?(:limit_value) &&
+          issuable_collection.limit_value.nil?
+
+        raise 'Collection must have a limit applied for preloading meta-data'
+      end
+
       # map has to be used here since using pluck or select will
       # throw an error when ordering issuables by priority which inserts
       # a new order into the collection.