Treat emphasis tags as excluding other notations

And exclusive notations don't exclude other exclusive notations.

Author: aycabta

lib/rdoc/markup/attr_span.rb

@@ -17,7 +17,7 @@ def initialize(length, exclusive)
   def set_attrs(start, length, bits)
     updated = false
     for i in start ... (start+length)
-      if (@exclusive & @attrs[i]) == 0
+      if (@exclusive & @attrs[i]) == 0 || (@exclusive | bits) != 0
         @attrs[i] |= bits
         updated = true
       end

lib/rdoc/markup/attribute_manager.rb

@@ -75,13 +75,13 @@ def initialize
     @exclusive_bitmap = 0
     @attributes = RDoc::Markup::Attributes.new
 
-    add_word_pair "*", "*", :BOLD
-    add_word_pair "_", "_", :EM
+    add_word_pair "*", "*", :BOLD, true
+    add_word_pair "_", "_", :EM, true
     add_word_pair "+", "+", :TT, true
 
-    add_html "em", :EM
-    add_html "i",  :EM
-    add_html "b",  :BOLD
+    add_html "em", :EM, true
+    add_html "i",  :EM, true
+    add_html "b",  :BOLD, true
     add_html "tt",   :TT, true
     add_html "code", :TT, true
   end

test/rdoc/test_rdoc_markup_attribute_manager.rb

@@ -250,6 +250,7 @@ def test_exclude_tag
     assert_equal '<CODE>aaa</CODE>[:symbol]', output('+aaa+[:symbol]')
     assert_equal '<CODE>aaa[:symbol]</CODE>', output('+aaa[:symbol]+')
     assert_equal 'aaa[:symbol]', output('aaa[:symbol]')
+    assert_equal '<B><CODE>index</CODE><B>', output('<b><tt>index</tt></b>')
   end
 
   def test_exclude_tag_flow