Stop multiple switches from trashing arguments

lib/slop.rb

@@ -466,8 +466,12 @@ def execute_option(option, argument, index, item = nil)
       return
     end
 
-    @trash << index + 1 unless item && item.end_with?("=#{argument}")
-    option.value = argument
+    if argument
+      @trash << index + 1 unless item && item.end_with?("=#{argument}")
+      option.value = argument
+    else
+      option.value = option.count > 0
+    end
 
     if option.match? && !argument.match(option.config[:match])
       raise InvalidArgumentError, "#{argument} is an invalid argument"
@@ -485,11 +489,11 @@ def execute_option(option, argument, index, item = nil)
   #
   # Returns nothing.
   def execute_multiple_switches(option, argument, index)
-    execute_option(option, argument, index)
+    execute_option(option, nil, index)
     argument.split('').each do |key|
       opt = fetch_option(key)
       opt.count += 1
-      execute_option(opt, argument, index, key)
+      execute_option(opt, nil, index, key)
     end
   end
 

test/slop_test.rb

@@ -218,6 +218,12 @@ def temp_stderr
     assert_equal 'abc123', opts[:f]
   end
 
+  test "muiltiple_switches should not trash arguments" do
+    opts = Slop.new{ on :f; on :b }
+    args = opts.parse!(%w'-fb foo')
+    assert_equal %w'foo', args
+  end
+
   test "setting/getting the banner" do
     opts = Slop.new :banner => 'foo'
     assert_equal 'foo', opts.banner