3 files changed, 58 insertions, 0 deletions
diff --git a/activerecord/test/cases/relation/delete_all_test.rb b/activerecord/test/cases/relation/delete_all_test.rb
index d1c13fa1b5..9b76936b7e 100644
--- a/activerecord/test/cases/relation/delete_all_test.rb
+++ b/activerecord/test/cases/relation/delete_all_test.rb
@@ -99,4 +99,23 @@ class DeleteAllTest < ActiveRecord::TestCase
     assert_raise(ActiveRecord::RecordNotFound) { posts(:thinking) }
     assert posts(:welcome)
   end
+
+  def test_delete_all_with_annotation_includes_a_query_comment
+    davids = Author.where(name: "David").annotate("deleting all")
+
+    assert_sql(%r{/\* deleting all \*/}) do
+      assert_difference("Author.count", -1) { davids.delete_all }
+    end
+  end
+
+  def test_delete_all_without_annotation_does_not_include_an_empty_comment
+    davids = Author.where(name: "David")
+
+    log = capture_sql do
+      assert_difference("Author.count", -1) { davids.delete_all }
+    end
+
+    assert_not_predicate log, :empty?
+    assert_predicate log.select { |query| query.match?(%r{/\*}) }, :empty?
+  end
 end
diff --git a/activerecord/test/cases/relation/merging_test.rb b/activerecord/test/cases/relation/merging_test.rb
index 224e4f39a8..5c5e760e34 100644
--- a/activerecord/test/cases/relation/merging_test.rb
+++ b/activerecord/test/cases/relation/merging_test.rb
@@ -135,6 +135,18 @@ class RelationMergingTest < ActiveRecord::TestCase
     relation = Post.all.merge(Post.order(Arel.sql("title LIKE '%?'")))
     assert_equal ["title LIKE '%?'"], relation.order_values
   end
+
+  def test_merging_annotations_respects_merge_order
+    assert_sql(%r{/\* foo \*/ /\* bar \*/}) do
+      Post.annotate("foo").merge(Post.annotate("bar")).first
+    end
+    assert_sql(%r{/\* bar \*/ /\* foo \*/}) do
+      Post.annotate("bar").merge(Post.annotate("foo")).first
+    end
+    assert_sql(%r{/\* foo \*/ /\* bar \*/ /\* baz \*/ /\* qux \*/}) do
+      Post.annotate("foo").annotate("bar").merge(Post.annotate("baz").annotate("qux")).first
+    end
+  end
 end
 
 class MergingDifferentRelationsTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/relation/update_all_test.rb b/activerecord/test/cases/relation/update_all_test.rb
index 0500574f28..526f926841 100644
--- a/activerecord/test/cases/relation/update_all_test.rb
+++ b/activerecord/test/cases/relation/update_all_test.rb
@@ -241,6 +241,33 @@ class UpdateAllTest < ActiveRecord::TestCase
     end
   end
 
+  def test_update_all_with_annotation_includes_a_query_comment
+    tag = Tag.first
+
+    assert_sql(%r{/\* updating all \*/}) do
+      Post.tagged_with(tag.id).annotate("updating all").update_all(title: "rofl")
+    end
+
+    posts = Post.tagged_with(tag.id).all.to_a
+    assert_operator posts.length, :>, 0
+    posts.each { |post| assert_equal "rofl", post.title }
+  end
+
+  def test_update_all_without_annotation_does_not_include_an_empty_comment
+    tag = Tag.first
+
+    log = capture_sql do
+      Post.tagged_with(tag.id).update_all(title: "rofl")
+    end
+
+    assert_not_predicate log, :empty?
+    assert_predicate log.select { |query| query.match?(%r{/\*}) }, :empty?
+
+    posts = Post.tagged_with(tag.id).all.to_a
+    assert_operator posts.length, :>, 0
+    posts.each { |post| assert_equal "rofl", post.title }
+  end
+
   # Oracle UPDATE does not support ORDER BY
   unless current_adapter?(:OracleAdapter)
     def test_update_all_ignores_order_without_limit_from_association