[Haml] Fix line-number-reporting with certain sorts of filters.

Closes gh-104

doc-src/HAML_CHANGELOG.md

@@ -12,6 +12,8 @@
   that return strings in Rails 3.
   This is [the same deprecation that exists in Rails 3](http://github.com/rails/rails/commit/9de83050d3a4b260d4aeb5d09ec4eb64f913ba64).
 
+* Make sure line numbers are reported correctly when filters are being used.
+
 ## 2.2.21
 
 [Tagged on GitHub](http://github.com/nex3/haml/commit/2.2.21).

lib/haml/filters.rb

@@ -100,8 +100,10 @@ module Haml
           if contains_interpolation?(text)
             return if options[:suppress_eval]
 
-            push_script <<RUBY, :escape_html => false
-find_and_preserve(#{filter.inspect}.render_with_options(#{unescape_interpolation(text)}, _hamlout.options))
+            text = unescape_interpolation(text).gsub("\\n", "\n")
+            newline if text.gsub!(/\n"\Z/, "\\n\"")
+            push_script <<RUBY.strip, :escape_html => false
+find_and_preserve(#{filter.inspect}.render_with_options(#{text}, _hamlout.options))
 RUBY
             return
           end
@@ -113,6 +115,10 @@ RUBY
           else
             push_text(rendered.rstrip)
           end
+
+          (text.count("\n") - 1).times {newline}
+          resolve_newlines
+          newline
         end
       end
 

lib/haml/precompiler.rb

@@ -189,7 +189,6 @@ END
         if flat?
           push_flat(@line)
           @line = @next_line
-          newline
           next
         end
 

test/haml/engine_test.rb

@@ -80,6 +80,11 @@ MESSAGE
     "!!!\n\n  bar" => ["Illegal nesting: nesting within a header command is illegal.", 3],
     "foo\n:ruby\n  1\n  2\n  3\n- raise 'foo'" => ["foo", 6],
     "foo\n:erb\n  1\n  2\n  3\n- raise 'foo'" => ["foo", 6],
+    "foo\n:plain\n  1\n  2\n  3\n- raise 'foo'" => ["foo", 6],
+    "foo\n:plain\n  1\n  2\n  3\n4\n- raise 'foo'" => ["foo", 7],
+    "foo\n:plain\n  1\n  2\n  3\#{''}\n- raise 'foo'" => ["foo", 6],
+    "foo\n:plain\n  1\n  2\n  3\#{''}\n4\n- raise 'foo'" => ["foo", 7],
+    "foo\n:plain\n  1\n  2\n  \#{raise 'foo'}" => ["foo", 5],
     "= raise 'foo'\nfoo\nbar\nbaz\nbang" => ["foo", 1],
   }