Restore connection_id on error.

1 files changed, 12 insertions, 0 deletions

diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index 83e207a260..2d778e9e90 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -39,6 +39,18 @@ class QueryCacheTest < ActiveRecord::TestCase
     assert ActiveRecord::Base.connection.query_cache_enabled, 'cache on'
   end
 
+  def test_exceptional_middleware_assigns_original_connection_id_on_error
+    connection_id = ActiveRecord::Base.connection_id
+
+    mw = ActiveRecord::QueryCache.new lambda { |env|
+      ActiveRecord::Base.connection_id = self.object_id
+      raise "lol borked"
+    }
+    assert_raises(RuntimeError) { mw.call({}) }
+
+    assert_equal connection_id, ActiveRecord::Base.connection_id 
+  end
+
   def test_middleware_delegates
     called = false
     mw = ActiveRecord::QueryCache.new lambda { |env|