Remove unnecessary &block from Range#sum and add tests for (num..float).sum

activesupport/lib/active_support/core_ext/enumerable.rb

@@ -115,7 +115,7 @@ def none?(&block)
 class Range #:nodoc:
   # Optimize range sum to use arithmetic progression if a block is not given and
   # we have a range of numeric values.
-  def sum(identity=0, &block)
+  def sum(identity = 0)
     return super if block_given? || !(first.instance_of?(Integer) && last.instance_of?(Integer))
     actual_last = exclude_end? ? (last - 1) : last
     (actual_last - first + 1) * (actual_last + first) / 2

activesupport/test/core_ext/enumerable_test.rb

@@ -66,6 +66,7 @@ def test_enumerable_sums
     assert_equal 10, (1..4).sum
     assert_equal 6, (1...4).sum
     assert_equal 'abc', ('a'..'c').sum
+    assert_raises(NoMethodError) { 1..2.5.sum }
   end
 
   def test_each_with_object