Clean up whitespace collapsing a bit

lib/liquid/block.rb

@@ -7,8 +7,8 @@ module Liquid
     FullToken         = /^#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}$/o
     ContentOfVariable = /^#{VariableStart}(.*)#{VariableEnd}$/o
 
-    def self.blank?
-      false
+    def blank?
+      @blank || false
     end
 
     def parse(tokens)
@@ -25,14 +25,13 @@ module Liquid
             # proceed
             if block_delimiter == $1
               end_tag
-              @blank = true if self.class.blank?
               return
             end
 
             # fetch the tag from registered blocks
             if tag = Template.tags[$1]
               new_tag = tag.new($1, $2, tokens)
-              @blank = false if new_tag.is_a?(Block) && !new_tag.blank
+              @blank = false unless new_tag.blank?
               @nodelist << new_tag
             else
               # this tag is not registered with the system

lib/liquid/tag.rb

@@ -19,8 +19,8 @@ module Liquid
       ''
     end
 
-    def self.blank?
-      true
+    def blank?
+      @blank || true
     end
   end # Tag
 end # Tag

lib/liquid/tags/capture.rb

@@ -31,7 +31,7 @@ module Liquid
       ''
     end
 
-    def self.blank?
+    def blank?
       true
     end
   end

lib/liquid/tags/comment.rb

@@ -4,7 +4,7 @@ module Liquid
       ''
     end
 
-    def self.blank?
+    def blank?
       true
     end
   end

lib/liquid/tags/increment.rb

@@ -28,7 +28,9 @@ module Liquid
       value.to_s
     end
   
-    private
+    def blank?
+      false
+    end
   end
   
   Template.register_tag('increment', Increment)

test/liquid/blank_test.rb

@@ -61,6 +61,10 @@ class BlankTest < Test::Unit::TestCase
     assert_template_result(body*(N+1), wrap(body))
   end
 
+  def test_increment_is_not_blank
+    assert_template_result(" 0"*2*(N+1), wrap("{% assign foo = 0 %} {% increment foo %} {% decrement foo %}"))
+  end
+
   def test_raw_is_not_blank
     assert_template_result("  "*(N+1), wrap(" {% raw %} {% endraw %}"))
   end