Revert "Merge pull request #23346 from kamipo/refactor_oid_money_precision"

This reverts commit ff835f90800a3e4122d64606cb328908c2e0e071, reversing
changes made to c4d85dfbc71043e2a746acd310e32f4f04db801a.

Reason: This broke the tests. We will add back after investigated.

2 files changed, 9 insertions, 5 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
index 78039b719c..2163674019 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
@@ -3,14 +3,12 @@ module ActiveRecord
     module PostgreSQL
       module OID # :nodoc:
         class Money < Type::Decimal # :nodoc:
+          class_attribute :precision
+
           def type
             :money
           end
 
-          def precision
-            19
-          end
-
           def scale
             2
           end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 725173d995..2de6fbfaf0 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -213,7 +213,7 @@ module ActiveRecord
         @statements = StatementPool.new @connection,
                                         self.class.type_cast_config_to_integer(config.fetch(:statement_limit) { 1000 })
 
-        if postgresql_version < 80300
+        if postgresql_version < 80200
           raise "Your version of PostgreSQL (#{postgresql_version}) is too old, please upgrade!"
         end
 
@@ -645,6 +645,12 @@ module ActiveRecord
         # connected server's characteristics.
         def connect
           @connection = PGconn.connect(@connection_parameters)
+
+          # Money type has a fixed precision of 10 in PostgreSQL 8.2 and below, and as of
+          # PostgreSQL 8.3 it has a fixed precision of 19. PostgreSQLColumn.extract_precision
+          # should know about this but can't detect it there, so deal with it here.
+          OID::Money.precision = (postgresql_version >= 80300) ? 19 : 10
+
           configure_connection
         rescue ::PG::Error => error
           if error.message.include?("does not exist")