Errors thrown for improper tabulation.

git-svn-id: svn://hamptoncatlin.com/haml/trunk@314 7063305b-7217-0410-af8c-cdc13e5119b9

lib/haml/engine.rb

@@ -201,14 +201,24 @@ module Haml
             
             if !suppress_render
               line_empty = old_line.empty?
+
               process_indent(old_tabs, old_line) unless line_empty
               flat = @flat_spaces != -1
 
+
+              if !flat && old_spaces != old_tabs * 2
+                raise SyntaxError.new("Illegal Indentation: Only two space characters are allowed as tabulation.")
+              end
+
               if flat
                 push_flat(old_line, old_spaces)
               elsif !line_empty
                 process_line(old_line, old_index, block_opened)
               end
+
+              if @flat_spaces == -1 && tabs - old_tabs > 1
+                raise SyntaxError.new("Illegal Indentation: Indenting more than once per line is illegal.")
+              end
             end
           end
           
@@ -655,6 +665,9 @@ module Haml
     # Counts the tabulation of a line.
     def count_soft_tabs(line)
       spaces = line.index(/[^ ]/)
+      if line[spaces] == ?\t
+        raise SyntaxError.new("Illegal Indentation: Only two space characters are allowed as tabulation.")
+      end
       [spaces, spaces/2]
     end
     

test/haml/engine_test.rb

@@ -121,7 +121,8 @@ class EngineTest < Test::Unit::TestCase
   def test_syntax_errors
     errs = [ "!!!\n  a", "a\n  b", "a\n:foo\nb", "/ a\n  b",
       "% a", "%p a\n  b", "a\n%p=\nb", "%p=\n  a",
-      "a\n%p~\nb", "a\n~\nb", "%p/\n  a"
+      "a\n%p~\nb", "a\n~\nb", "%p/\n  a", "%p\n \t%a b",
+      "%a\n b\nc", "%a\n    b\nc"
     ]
     errs.each do |err|
       begin