avoid extra method calls for appending newlines

before:

        ');@output_buffer.append= ( content_icon row[:content] );@output_buffer.safe_concat('
');@output_buffer.safe_concat('        ');@output_buffer.append= ( spinner_img );@output_buffer.safe_concat('
');@output_buffer.safe_concat('      </td>
      <td class="content">
        ');@output_buffer.append= ( content_link row[:content] );@output_buffer.safe_concat('
');@output_buffer.safe_concat('      </td>
      <td class="message">
');

after:

        ';@output_buffer.append=( content_icon row[:content] );@output_buffer.safe_append='
        ';@output_buffer.append=( spinner_img );@output_buffer.safe_append='
      </td>
      <td class="content">
        ';@output_buffer.append=( content_link row[:content] );@output_buffer.safe_append='
      </td>
      <td class="message">
';

1 files changed, 27 insertions, 1 deletions

diff --git a/actionpack/lib/action_view/template/handlers/erb.rb b/actionpack/lib/action_view/template/handlers/erb.rb
index 52534655eb..7d7a7af51d 100644
--- a/actionpack/lib/action_view/template/handlers/erb.rb
+++ b/actionpack/lib/action_view/template/handlers/erb.rb
@@ -6,12 +6,23 @@ module ActionView
     module Handlers
       class Erubis < ::Erubis::Eruby
         def add_preamble(src)
+          @newline_pending = 0
           src << "@output_buffer = output_buffer || ActionView::OutputBuffer.new;"
         end
 
         def add_text(src, text)
           return if text.empty?
-          src << "@output_buffer.safe_append='" << escape_text(text) << "';"
+
+          if text == "\n"
+            @newline_pending += 1
+          else
+            src << "@output_buffer.safe_append='"
+            src << "\n" * @newline_pending if @newline_pending > 0
+            src << escape_text(text)
+            src << "';"
+
+            @newline_pending = 0
+          end
         end
 
         # Erubis toggles <%= and <%== behavior when escaping is enabled.
@@ -28,6 +39,7 @@ module ActionView
         BLOCK_EXPR = /\s+(do|\{)(\s*\|[^|]*\|)?\s*\Z/
 
         def add_expr_literal(src, code)
+          flush_newline_if_pending(src)
           if code =~ BLOCK_EXPR
             src << '@output_buffer.append= ' << code
           else
@@ -36,6 +48,7 @@ module ActionView
         end
 
         def add_expr_escaped(src, code)
+          flush_newline_if_pending(src)
           if code =~ BLOCK_EXPR
             src << "@output_buffer.safe_append= " << code
           else
@@ -43,9 +56,22 @@ module ActionView
           end
         end
 
+        def add_stmt(src, code)
+          flush_newline_if_pending(src)
+          super
+        end
+
         def add_postamble(src)
+          flush_newline_if_pending(src)
           src << '@output_buffer.to_s'
         end
+
+        def flush_newline_if_pending(src)
+          if @newline_pending > 0
+            src << "@output_buffer.safe_append='#{"\n" * @newline_pending}';"
+            @newline_pending = 0
+          end
+        end
       end
 
       class ERB