[Haml] Fix a bug with new attribute parsing.

Closes gh-18

lib/haml/precompiler.rb

@@ -617,7 +617,7 @@ END
         return name, [:dynamic, var]
       end
 
-      re = /((?:\\.|\#[^{]|[^#{quote}\\#])*)(#{quote}|#\{)/
+      re = /((?:\\.|\#[^{]|[^#{quote}\\#])*#?)(#{quote}|#\{)/
       content = []
       loop do
         return false unless scanner.scan(re)

test/haml/engine_test.rb

@@ -421,6 +421,10 @@ HAML
 HAML
   end
 
+  def test_new_attrs_with_hash
+    assert_equal("<a href='#'></a>\n", render('%a(href="#")'))
+  end
+
   # HTML escaping tests
 
   def test_ampersand_equals_should_escape