2 files changed, 47 insertions, 2 deletions
diff --git a/activerecord/test/cases/comment_test.rb b/activerecord/test/cases/comment_test.rb
index 9ab6607668..f2ec5d6518 100644
--- a/activerecord/test/cases/comment_test.rb
+++ b/activerecord/test/cases/comment_test.rb
@@ -119,8 +119,6 @@ if ActiveRecord::Base.connection.supports_comments?
         assert_match %r[t\.integer\s+"rating",\s+precision: 38,\s+comment: "I am running out of imagination"], output
       else
         assert_match %r[t\.integer\s+"rating",\s+comment: "I am running out of imagination"], output
-      end
-      unless current_adapter?(:OracleAdapter)
         assert_match %r[t\.index\s+.+\s+comment: "\\\"Very important\\\" index that powers all the performance.\\nAnd it's fun!"], output
         assert_match %r[t\.index\s+.+\s+name: "idx_obvious",\s+comment: "We need to see obvious comments"], output
       end
diff --git a/activerecord/test/cases/relation/where_clause_test.rb b/activerecord/test/cases/relation/where_clause_test.rb
index f3a81f3c70..e5eb159d36 100644
--- a/activerecord/test/cases/relation/where_clause_test.rb
+++ b/activerecord/test/cases/relation/where_clause_test.rb
@@ -181,6 +181,53 @@ class ActiveRecord::Relation
       assert_equal WhereClause.empty, WhereClause.empty.or(where_clause)
     end
 
+    test "or places common conditions before the OR" do
+      a = WhereClause.new(
+        [table["id"].eq(bind_param(1)), table["name"].eq(bind_param("Sean"))],
+      )
+      b = WhereClause.new(
+        [table["id"].eq(bind_param(1)), table["hair_color"].eq(bind_param("black"))],
+      )
+
+      common = WhereClause.new(
+        [table["id"].eq(bind_param(1))],
+      )
+
+      or_clause = WhereClause.new([table["name"].eq(bind_param("Sean"))])
+        .or(WhereClause.new([table["hair_color"].eq(bind_param("black"))]))
+
+      assert_equal common + or_clause, a.or(b)
+    end
+
+    test "or can detect identical or as being a common condition" do
+      common_or = WhereClause.new([table["name"].eq(bind_param("Sean"))])
+        .or(WhereClause.new([table["hair_color"].eq(bind_param("black"))]))
+
+      a = common_or + WhereClause.new([table["id"].eq(bind_param(1))])
+      b = common_or + WhereClause.new([table["foo"].eq(bind_param("bar"))])
+
+      new_or = WhereClause.new([table["id"].eq(bind_param(1))])
+        .or(WhereClause.new([table["foo"].eq(bind_param("bar"))]))
+
+      assert_equal common_or + new_or, a.or(b)
+    end
+
+    test "or will use only common conditions if one side only has common conditions" do
+      only_common = WhereClause.new([
+        table["id"].eq(bind_param(1)),
+        "foo = bar",
+      ])
+
+      common_with_extra = WhereClause.new([
+        table["id"].eq(bind_param(1)),
+        "foo = bar",
+        table["extra"].eq(bind_param("pluto")),
+      ])
+
+      assert_equal only_common, only_common.or(common_with_extra)
+      assert_equal only_common, common_with_extra.or(only_common)
+    end
+
     private
 
       def table