Fix error when assigning NaN to an integer column

Also covers any non-castable case by returning nil, which
is in-line with the intention of the former implementation,
but covers the odd cases which respond to to_i but raise
an error when it's called, such as NaN, Infinity and -Infinity.

Fixes #8757

Backport of #8781

Conflicts:
	activerecord/CHANGELOG.md
	activerecord/test/cases/column_test.rb

1 files changed, 6 insertions, 0 deletions

diff --git a/activerecord/test/cases/column_test.rb b/activerecord/test/cases/column_test.rb
index 8017a49827..77647d7986 100644
--- a/activerecord/test/cases/column_test.rb
+++ b/activerecord/test/cases/column_test.rb
@@ -56,6 +56,12 @@ module ActiveRecord
         column = Column.new("field", nil, "integer")
         assert_nil column.type_cast(Object.new)
       end
+
+      def test_type_cast_nan_and_infinity_to_integer
+        column = Column.new("field", nil, "integer")
+        assert_nil column.type_cast(Float::NAN)
+        assert_nil column.type_cast(1.0/0.0)
+      end
     end
   end
 end