use thread locals and an instance variable within QueryCache#BodyProxy to maintain appropriate linkage with AR database connection across threads

1 files changed, 4 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/query_cache.rb b/activerecord/lib/active_record/query_cache.rb
index 10c0dc6f2a..466d148901 100644
--- a/activerecord/lib/active_record/query_cache.rb
+++ b/activerecord/lib/active_record/query_cache.rb
@@ -28,9 +28,10 @@ module ActiveRecord
     end
 
     class BodyProxy # :nodoc:
-      def initialize(original_cache_value, target)
+      def initialize(original_cache_value, target, connection_id)
         @original_cache_value = original_cache_value
         @target               = target
+        @connection_id        = connection_id
       end
 
       def method_missing(method_sym, *arguments, &block)
@@ -48,6 +49,7 @@ module ActiveRecord
       def close
         @target.close if @target.respond_to?(:close)
       ensure
+        ActiveRecord::Base.connection_id = @connection_id
         ActiveRecord::Base.connection.clear_query_cache
         unless @original_cache_value
           ActiveRecord::Base.connection.disable_query_cache!
@@ -60,7 +62,7 @@ module ActiveRecord
       ActiveRecord::Base.connection.enable_query_cache!
 
       status, headers, body = @app.call(env)
-      [status, headers, BodyProxy.new(old, body)]
+      [status, headers, BodyProxy.new(old, body, ActiveRecord::Base.connection_id)]
     rescue Exception => e
       ActiveRecord::Base.connection.clear_query_cache
       unless old