3 files changed, 46 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 37db2be7a9..f4beeceb61 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -39,6 +39,16 @@ module ActiveRecord
       # :stopdoc:
       class << self
         attr_accessor :money_precision
+        def string_to_time(string)
+          return string unless String === string
+
+          case string
+          when 'infinity'  then 1.0 / 0.0
+          when '-infinity' then -1.0 / 0.0
+          else
+            super
+          end
+        end
       end
       # :startdoc:
 
@@ -349,6 +359,9 @@ module ActiveRecord
         return super unless column
 
         case value
+        when Float
+          return super unless value.infinite? && column.type == :datetime
+          "'#{value.to_s.downcase}'"
         when Numeric
           return super unless column.sql_type == 'money'
           # Not truly string input, so doesn't require (or allow) escape string syntax.
diff --git a/activerecord/lib/active_record/test_case.rb b/activerecord/lib/active_record/test_case.rb
index 29efbbcb8c..0d47eb3338 100644
--- a/activerecord/lib/active_record/test_case.rb
+++ b/activerecord/lib/active_record/test_case.rb
@@ -13,6 +13,13 @@ module ActiveRecord
       ActiveRecord::IdentityMap.clear
     end
 
+    # Backport skip to Ruby 1.8.  test/unit doesn't support it, so just
+    # make it a noop.
+    unless instance_methods.map(&:to_s).include?("skip")
+      def skip(message)
+      end
+    end
+
     def assert_date_from_db(expected, actual, message = nil)
       # SybaseAdapter doesn't have a separate column type just for dates,
       # so the time is in the string and incorrectly formatted
diff --git a/activerecord/test/cases/timestamp_test.rb b/activerecord/test/cases/timestamp_test.rb
index ceb1452afd..22d4cac422 100644
--- a/activerecord/test/cases/timestamp_test.rb
+++ b/activerecord/test/cases/timestamp_test.rb
@@ -14,6 +14,32 @@ class TimestampTest < ActiveRecord::TestCase
     @previously_updated_at = @developer.updated_at
   end
 
+  def test_load_infinity_and_beyond
+    unless current_adapter?(:PostgreSQLAdapter)
+      return skip("only tested on postgresql")
+    end
+
+    d = Developer.find_by_sql("select 'infinity'::timestamp as updated_at")
+    assert d.first.updated_at.infinite?, 'timestamp should be infinite'
+
+    d = Developer.find_by_sql("select '-infinity'::timestamp as updated_at")
+    time = d.first.updated_at
+    assert time.infinite?, 'timestamp should be infinite'
+    assert_operator time, :<, 0
+  end
+
+  def test_save_infinity_and_beyond
+    unless current_adapter?(:PostgreSQLAdapter)
+      return skip("only tested on postgresql")
+    end
+
+    d = Developer.create!(:name => 'aaron', :updated_at => 1.0 / 0.0)
+    assert_equal(1.0 / 0.0, d.updated_at)
+
+    d = Developer.create!(:name => 'aaron', :updated_at => -1.0 / 0.0)
+    assert_equal(-1.0 / 0.0, d.updated_at)
+  end
+
   def test_saving_a_changed_record_updates_its_timestamp
     @developer.name = "Jack Bauer"
     @developer.save!