From f0da48495c12a02f6dd9f3374aaa040672aef42a Mon Sep 17 00:00:00 2001
From: Dylan Thacker-Smith <Dylan.Smith@shopify.com>
Date: Thu, 3 Sep 2020 11:08:17 -0400
Subject: [PATCH] Default Block#blank? to false regardless of whether the body
 is blank

---
 lib/liquid/block.rb     | 11 -----------
 lib/liquid/tags/case.rb |  7 ++++++-
 lib/liquid/tags/for.rb  |  7 ++++++-
 lib/liquid/tags/if.rb   |  7 ++++++-
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/lib/liquid/block.rb b/lib/liquid/block.rb
index 9d7b752..7155490 100644
--- a/lib/liquid/block.rb
+++ b/lib/liquid/block.rb
@@ -4,11 +4,6 @@ module Liquid
   class Block < Tag
     MAX_DEPTH = 100
 
-    def initialize(tag_name, markup, options)
-      super
-      @blank = true
-    end
-
     def parse(tokens)
       @body = BlockBody.new
       while parse_body(@body, tokens)
@@ -20,10 +15,6 @@ module Liquid
       @body.render(context)
     end
 
-    def blank?
-      @blank
-    end
-
     def nodelist
       @body.nodelist
     end
@@ -64,8 +55,6 @@ module Liquid
       parse_context.depth += 1
       begin
         body.parse(tokens, parse_context) do |end_tag_name, end_tag_params|
-          @blank &&= body.blank?
-
           return false if end_tag_name == block_delimiter
           unless end_tag_name
             raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
diff --git a/lib/liquid/tags/case.rb b/lib/liquid/tags/case.rb
index f6e0e70..f65fe9b 100644
--- a/lib/liquid/tags/case.rb
+++ b/lib/liquid/tags/case.rb
@@ -21,11 +21,16 @@ module Liquid
     def parse(tokens)
       body = BlockBody.new
       body = @blocks.last.attachment while parse_body(body, tokens)
-      if blank?
+      @blank = @blocks.all? { |condition| condition.attachment.blank? }
+      if @blank
         @blocks.each { |condition| condition.attachment.remove_blank_strings }
       end
     end
 
+    def blank?
+      @blank
+    end
+
     def nodelist
       @blocks.map(&:attachment)
     end
diff --git a/lib/liquid/tags/for.rb b/lib/liquid/tags/for.rb
index bb03392..a323034 100644
--- a/lib/liquid/tags/for.rb
+++ b/lib/liquid/tags/for.rb
@@ -62,12 +62,17 @@ module Liquid
       if parse_body(@for_block, tokens)
         parse_body(@else_block, tokens)
       end
-      if blank?
+      @blank = @for_block.blank? && (@else_block.nil? || @else_block.blank?)
+      if @blank
         @for_block.remove_blank_strings
         @else_block&.remove_blank_strings
       end
     end
 
+    def blank?
+      @blank
+    end
+
     def nodelist
       @else_block ? [@for_block, @else_block] : [@for_block]
     end
diff --git a/lib/liquid/tags/if.rb b/lib/liquid/tags/if.rb
index 43c8b0a..bc03e18 100644
--- a/lib/liquid/tags/if.rb
+++ b/lib/liquid/tags/if.rb
@@ -31,11 +31,16 @@ module Liquid
     def parse(tokens)
       while parse_body(@blocks.last.attachment, tokens)
       end
-      if blank?
+      @blank = @blocks.all? { |condition| condition.attachment.blank? }
+      if @blank
         @blocks.each { |condition| condition.attachment.remove_blank_strings }
       end
     end
 
+    def blank?
+      @blank
+    end
+
     def unknown_tag(tag, markup, tokens)
       if ['elsif', 'else'].include?(tag)
         push_block(tag, markup)