Highlight: Only Strip Newlines/Carriage Returns, not Spaces

lib/jekyll/tags/highlight.rb

@@ -42,7 +42,7 @@ def initialize(tag_name, markup, tokens)
       def render(context)
         prefix = context["highlighter_prefix"] || ""
         suffix = context["highlighter_suffix"] || ""
-        code = super.to_s.strip
+        code = super.to_s.gsub(/^(\n|\r)+|(\n|\r)+$/, '')
 
         is_safe = !!context.registers[:site].safe
 

test/test_tags.rb

@@ -174,6 +174,46 @@ def highlight_block_with_opts(options_string)
     end
   end
 
+  context "post content has highlight tag with preceding spaces & lines" do
+    setup do
+      fill_post <<-EOS
+
+
+     [,1] [,2]
+[1,] FALSE TRUE
+[2,] FALSE TRUE
+EOS
+    end
+
+    should "only strip the preceding newlines" do
+      assert_match %{<pre><code class=\"language-text\" data-lang=\"text\">     [,1] [,2]}, @result
+    end
+  end
+
+  context "post content has highlight tag with preceding spaces & Windows-style newlines" do
+    setup do
+      fill_post "\r\n\r\n\r\n     [,1] [,2]"
+    end
+
+    should "only strip the preceding newlines" do
+      assert_match %{<pre><code class=\"language-text\" data-lang=\"text\">     [,1] [,2]}, @result
+    end
+  end
+
+  context "post content has highlight tag with only preceding spaces" do
+    setup do
+      fill_post <<-EOS
+     [,1] [,2]
+[1,] FALSE TRUE
+[2,] FALSE TRUE
+EOS
+    end
+
+    should "only strip the preceding newlines" do
+      assert_match %{<pre><code class=\"language-text\" data-lang=\"text\">     [,1] [,2]}, @result
+    end
+  end
+
   context "simple post with markdown and pre tags" do
     setup do
       @content = <<CONTENT