added failing spec for lambda with optional parameter

Author: tak1n

spec/ruby/core/proc/curry_spec.rb

@@ -124,6 +124,7 @@
   it "raises an ArgumentError if called on a lambda that requires fewer than _arity_ arguments" do
     lambda { @lambda_add.curry(4) }.should raise_error(ArgumentError)
     lambda { lambda { true }.curry(1) }.should raise_error(ArgumentError)
+    lambda { lambda {|a, b=nil|}.curry(5) }.should raise_error(ArgumentError)
   end
 
   it "calls the curried proc with the arguments if _arity_ arguments have been given" do

spec/tags/ruby/core/proc/curry_tags.txt

@@ -0,0 +1 @@
+fails:raises an ArgumentError if called on a lambda that requires fewer than _arity_ arguments