Fix for Rails 3.2.3 textarea helpers

Textarea helpers on 3.2.3 emit a newline after the opening textarea tag,
which caused Haml to mess up indenting and add an encoded newline to the
textarea content. This fixes the issue by replacing the first newline
with <haml:newline/> in the Haml buffer, and then changing it to a true
newline at render time.

doc-src/HAML_CHANGELOG.md

@@ -8,6 +8,9 @@
 * Respect Rails' `html_safe` flag when escaping attribute values
   (thanks to [Gerad Suyderhoud](https://github.com/gerad)).
 
+* Fix for Rails 3.2.3 textarea helpers
+  (thanks to [James Coleman](https://github.com/jcoleman) and others).
+
 ## 3.1.4
 
 * Fix the use of `FormBuilder#block` with a label in Haml.

lib/haml/helpers/action_view_mods.rb

@@ -256,3 +256,5 @@ module ActionView
     end
   end
 end
+
+require "haml/helpers/rails_323_textarea_fix" if Haml::Util.ap_geq?("3.2.3")

lib/haml/helpers/rails_323_textarea_fix.rb

@@ -0,0 +1,49 @@
+# Rails 3.2.3's form helpers add a newline after opening textareas, which can
+# cause problems with newlines being considered content rather than markup.
+# These changes fix the issue by making the helpers emit "<haml:newline/>"
+# rather than the leading newline. The tag is then replaced by a newline after
+# rendering.
+#
+# This should be considered nothing more than an emergency hotfix to ensure
+# compatibility with the latest version of Rails, made at a moment when the Haml
+# project is transitioning to a new maintainer.
+
+module AbstractController
+  module Rendering
+    def render_to_body_with_haml(options = {})
+      if rendered = render_to_body_without_haml(options)
+        rendered.gsub('<haml:newline/>', "\n").html_safe
+      end
+    end
+    alias_method_chain :render_to_body, :haml
+  end
+end
+
+module ActionView
+
+  class Renderer
+    def render_template_with_haml(context, options)
+      if rendered = render_template_without_haml(context, options)
+        rendered.gsub('<haml:newline/>', "\n").html_safe
+      end
+    end
+    alias_method_chain :render_template, :haml
+  end
+
+  module Helpers
+    module TagHelper
+      private
+
+      def content_tag_string_with_haml(name, content, options, escape = true)
+        if name.to_sym == :textarea
+          tag_options = tag_options(options, escape) if options
+          content = ERB::Util.h(content) if escape
+          "<#{name}#{tag_options}><haml:newline/>#{content}</#{name}>".html_safe
+        else
+          content_tag_string_without_haml(name, content, options, escape)
+        end
+      end
+      alias_method_chain :content_tag_string, :haml
+    end
+  end
+end

test/haml/helper_test.rb

@@ -133,17 +133,30 @@ HTML
 HAML
   end
 
-  def test_text_area
-    assert_equal(%(<textarea id="body" name="body">Foo&#x000A;Bar&#x000A; Baz&#x000A;   Boom</textarea>\n),
-                 render('= text_area_tag "body", "Foo\nBar\n Baz\n   Boom"', :action_view))
+  if Haml::Util.ap_geq?("3.2.3")
+    def test_text_area
+      assert_equal(%(<textarea id="body" name="body">\nFoo&#x000A;Bar&#x000A; Baz&#x000A;   Boom</textarea>\n),
+                   render('= text_area_tag "body", "Foo\nBar\n Baz\n   Boom"', :action_view))
 
-    assert_equal(%(<textarea cols="40" id="post_body" name="post[body]" rows="20">Foo bar&#x000A;baz</textarea>\n),
-                 render('= text_area :post, :body', :action_view))    
+      assert_equal(%(<textarea cols="40" id="post_body" name="post[body]" rows="20">\nFoo bar&#x000A;baz</textarea>\n),
+                   render('= text_area :post, :body', :action_view))
 
-    assert_equal(%(<pre>Foo bar&#x000A;   baz</pre>\n),
-                 render('= content_tag "pre", "Foo bar\n   baz"', :action_view))    
+      assert_equal(%(<pre>Foo bar&#x000A;   baz</pre>\n),
+                   render('= content_tag "pre", "Foo bar\n   baz"', :action_view))
+    end
+  else
+    def test_text_area
+      assert_equal(%(<textarea id="body" name="body">Foo&#x000A;Bar&#x000A; Baz&#x000A;   Boom</textarea>\n),
+                   render('= text_area_tag "body", "Foo\nBar\n Baz\n   Boom"', :action_view))
+
+      assert_equal(%(<textarea cols="40" id="post_body" name="post[body]" rows="20">Foo bar&#x000A;baz</textarea>\n),
+                   render('= text_area :post, :body', :action_view))
+
+      assert_equal(%(<pre>Foo bar&#x000A;   baz</pre>\n),
+                   render('= content_tag "pre", "Foo bar\n   baz"', :action_view))
+    end
   end
-  
+
   def test_capture_haml
     assert_equal(<<HTML, render(<<HAML))
 "<p>13</p>\\n"