Respect the current `connected?` method when calling `cache`

Before we enable query caching we check if the connection is
connected. Before this fix we were always checking against the main
connection, and not the model connection.

2 files changed, 17 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/query_cache.rb b/activerecord/lib/active_record/query_cache.rb
index ca12a603da..07d863d15e 100644
--- a/activerecord/lib/active_record/query_cache.rb
+++ b/activerecord/lib/active_record/query_cache.rb
@@ -5,7 +5,7 @@ module ActiveRecord
       # Enable the query cache within the block if Active Record is configured.
       # If it's not, it will execute the given block.
       def cache(&block)
-        if ActiveRecord::Base.connected?
+        if connected?
           connection.cache(&block)
         else
           yield
@@ -15,7 +15,7 @@ module ActiveRecord
       # Disable the query cache within the block if Active Record is configured.
       # If it's not, it will execute the given block.
       def uncached(&block)
-        if ActiveRecord::Base.connected?
+        if connected?
           connection.uncached(&block)
         else
           yield
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index 199a41d428..25b16ae142 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -174,6 +174,21 @@ class QueryCacheTest < ActiveRecord::TestCase
     ActiveRecord::Base.configurations = conf
   end
 
+  def test_cache_is_not_available_when_using_a_not_connected_connection
+    spec_name = Task.connection_specification_name
+    conf = ActiveRecord::Base.configurations['arunit'].merge('name' => 'test2')
+    ActiveRecord::Base.connection_handler.establish_connection(conf)
+    Task.connection_specification_name = "test2"
+    refute Task.connected?
+
+    Task.cache do
+      assert_queries(2) { Task.find(1); Task.find(1) }
+    end
+  ensure
+    ActiveRecord::Base.connection_handler.remove_connection(Task.connection_specification_name)
+    Task.connection_specification_name = spec_name
+  end
+
   def test_query_cache_doesnt_leak_cached_results_of_rolled_back_queries
     ActiveRecord::Base.connection.enable_query_cache!
     post = Post.first