Adds race condition with all weights 0.

Author: Peter de Ruijter

lib/array.rb

@@ -1,7 +1,6 @@
 class Array
   def weighted_sample(weights=nil)
-    weights ||= Array.new(length, 1.0)
-
+    weights = Array.new(length, 1.0) if weights.nil? || weights.sum == 0
     total = weights.sum
 
     # The total sum of weights is multiplied by a random number

spec/array_spec.rb

@@ -41,6 +41,10 @@
       before { Kernel.stub(:rand) { 1 } }
       subject { array.weighted_sample([0, 0, 0, 0]) }
       it { should eq 4 }
+      context "random 0" do
+        before { Kernel.stub(:rand) { 0 } }
+        it { should eq 1 }
+      end
     end
   end
 end