Merge pull request #38583 from kamipo/fix_unscope_with_arel_sql

Fix `unscope` when an `eq` node which has no arel attribute

activerecord/lib/arel.rb

@@ -53,7 +53,7 @@ def self.fetch_attribute(value, &block) # :nodoc:
          Arel::Nodes::GreaterThan, Arel::Nodes::GreaterThanOrEqual
       if value.left.is_a?(Arel::Attributes::Attribute)
         yield value.left
-      else
+      elsif value.right.is_a?(Arel::Attributes::Attribute)
         yield value.right
       end
     when Arel::Nodes::Or

activerecord/test/cases/relations_test.rb

@@ -2050,6 +2050,18 @@ def test_unscope_specific_where_value
     assert_equal 1, posts.unscope(where: :body).count
   end
 
+  def test_unscope_with_arel_sql
+    posts = Post.where(Arel.sql("'Welcome to the weblog'").eq(Post.arel_attribute(:title)))
+
+    assert_equal 1, posts.count
+    assert_equal Post.count, posts.unscope(where: :title).count
+
+    posts = Post.where(Arel.sql("posts.title").eq("Welcome to the weblog"))
+
+    assert_equal 1, posts.count
+    assert_equal 1, posts.unscope(where: :title).count
+  end
+
   def test_unscope_grouped_where
     posts = Post.where(
       title: ["Welcome to the weblog", "So I was thinking", nil]