Don't use `collection.table_name` in `collection_cache_key`

Because `collection.table_name` doesn't respect table alias.
Use `collection.arel_attribute` instead.

2 files changed, 19 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/collection_cache_key.rb b/activerecord/lib/active_record/collection_cache_key.rb
index b1937a3c68..f3e6516414 100644
--- a/activerecord/lib/active_record/collection_cache_key.rb
+++ b/activerecord/lib/active_record/collection_cache_key.rb
@@ -13,7 +13,7 @@ module ActiveRecord
         end
       else
         column_type = type_for_attribute(timestamp_column.to_s)
-        column = "#{connection.quote_table_name(collection.table_name)}.#{connection.quote_column_name(timestamp_column)}"
+        column = connection.column_name_from_arel_node(collection.arel_attribute(timestamp_column))
         select_values = "COUNT(*) AS #{connection.quote_column_name("size")}, MAX(%s) AS timestamp"
 
         if collection.has_limit_or_offset?
diff --git a/activerecord/test/cases/collection_cache_key_test.rb b/activerecord/test/cases/collection_cache_key_test.rb
index dbe6857487..c137693211 100644
--- a/activerecord/test/cases/collection_cache_key_test.rb
+++ b/activerecord/test/cases/collection_cache_key_test.rb
@@ -55,6 +55,24 @@ module ActiveRecord
       assert_equal last_developer_timestamp.to_s(ActiveRecord::Base.cache_timestamp_format), $3
     end
 
+    test "cache_key for relation with table alias" do
+      table_alias = Developer.arel_table.alias("omg_developers")
+      table_metadata = ActiveRecord::TableMetadata.new(Developer, table_alias)
+      predicate_builder = ActiveRecord::PredicateBuilder.new(table_metadata)
+
+      developers = ActiveRecord::Relation.create(Developer, table_alias, predicate_builder)
+      developers = developers.where(salary: 100000).order(updated_at: :desc)
+      last_developer_timestamp = developers.first.updated_at
+
+      assert_match(/\Adevelopers\/query-(\h+)-(\d+)-(\d+)\z/, developers.cache_key)
+
+      /\Adevelopers\/query-(\h+)-(\d+)-(\d+)\z/ =~ developers.cache_key
+
+      assert_equal Digest::MD5.hexdigest(developers.to_sql), $1
+      assert_equal developers.count.to_s, $2
+      assert_equal last_developer_timestamp.to_s(ActiveRecord::Base.cache_timestamp_format), $3
+    end
+
     test "it triggers at most one query" do
       developers = Developer.where(name: "David")