pools are 1:1 with spec now rather than 1:1 with class

activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb

@@ -320,10 +320,12 @@ class ConnectionHandler
 
       def initialize(pools = {})
         @connection_pools = pools
+        @class_to_pool    = {}
       end
 
       def establish_connection(name, spec)
-        @connection_pools[name] = ConnectionAdapters::ConnectionPool.new(spec)
+        @connection_pools[spec] ||= ConnectionAdapters::ConnectionPool.new(spec)
+        @class_to_pool[name] = @connection_pools[spec]
       end
 
       # Returns true if there are any active connections among the connection
@@ -374,16 +376,17 @@ def connected?(klass)
       # can be used as an argument for establish_connection, for easily
       # re-establishing the connection.
       def remove_connection(klass)
-        pool = @connection_pools.delete(klass.name)
+        pool = @class_to_pool.delete(klass.name)
         return nil unless pool
 
+        @connection_pools.delete pool.spec
         pool.automatic_reconnect = false
         pool.disconnect!
         pool.spec.config
       end
 
       def retrieve_connection_pool(klass)
-        pool = @connection_pools[klass.name]
+        pool = @class_to_pool[klass.name]
         return pool if pool
         return nil if ActiveRecord::Base == klass
         retrieve_connection_pool klass.superclass

activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb

@@ -82,7 +82,8 @@ def self.resolve_string_connection(spec) # :nodoc:
 
     def self.resolve_hash_connection(spec) # :nodoc:
       spec = spec.symbolize_keys
-      unless spec.key?(:adapter) then raise AdapterNotSpecified, "database configuration does not specify adapter" end
+
+      raise(AdapterNotSpecified, "database configuration does not specify adapter") unless spec.key?(:adapter)
 
       begin
         require "active_record/connection_adapters/#{spec[:adapter]}_adapter"

activerecord/test/cases/connection_adapters/connection_handler_test.rb

@@ -40,8 +40,6 @@ def test_retrieve_connection_pool_uses_superclass_when_no_subclass_connection
 
       def test_retrieve_connection_pool_uses_superclass_pool_after_subclass_establish_and_remove
         @handler.establish_connection 'north america', Base.connection_pool.spec
-        assert_not_same @handler.retrieve_connection_pool(@klass),
-          @handler.retrieve_connection_pool(@subklass)
 
         @handler.remove_connection @subklass
         assert_same @handler.retrieve_connection_pool(@klass),

activerecord/test/cases/multiple_db_test.rb

@@ -85,7 +85,6 @@ def test_transactions_across_databases
   end
 
   def test_arel_table_engines
-    assert_not_equal Entrant.arel_engine, Course.arel_engine
     assert_equal Entrant.arel_engine, Bird.arel_engine
   end
 end