Fixed yet another diff-breaking edge case. This one had to do with

inserting italicized text right before some existing italicized text.

NEWS

@@ -1,3 +1,7 @@
+1.3.12: May 3, 2008:
+ * Fixed yet another diff-breaking edge case. This one had to do with
+   inserting italicized text right before some existing italicized text.
+
 1.3.11: May 2, 2008
  * Fixed another bug that prevented diffs from working. This time, those with
    <br/> tags didn't parse correctly.

controller/Html_differ.py

@@ -182,6 +182,11 @@ class Html_differ( HTMLParser ):
         open_del_items = []
         open_ins_items = []
 
+    if len( open_del_items ):
+      result_a.extend( open_del_items )
+    if len( open_ins_items ):
+      result_b.extend( open_ins_items )
+
     return ( result_a, result_b )
 
   def diff_lists( self, a, b ):

controller/test/Test_html_differ.py

@@ -75,6 +75,15 @@ class Test_html_differ( object ):
 
     assert result == 'foo <del class="diff modified">bar baz </del><ins class="diff modified"><i>bar whee baz</i> </ins>quux'
 
+  def test_diff_with_italics_twice( self ):
+    a = 'foo bar baz quux <i>foo</i>'
+    b = 'foo bar baz quux <i>whee</i><i>foo</i>'
+
+    result = self.differ.diff( a, b )
+
+    # note the screwy placement of the <ins></ins> tags. this is the best the differ can do for now
+    assert result == 'foo bar baz quux <i><ins class="diff">whee</i><i></ins>foo</i>'
+
   def test_diff_with_link( self ):
     a = 'foo bar baz quux'
     b = 'foo bar <a href="whee">baz</a> quux'
@@ -181,6 +190,19 @@ class Test_html_differ( object ):
     assert new_a == [ 'foo ', 'bar baz ', 'quux' ]
     assert new_b == [ 'foo ', '<i>bar whee baz</i> ', 'quux' ]
 
+  def test_prepare_lists_with_italics_twice( self ):
+    a = [ 'foo ', 'bar ', 'baz ', 'quux ', '<i>', 'foo', '</i>' ]
+    b = [ 'foo ', 'bar ', 'baz ', 'quux ', '<i>', 'whee', '</i>', '<i>', 'foo', '</i>' ]
+
+    result = self.differ.prepare_lists( a, b )
+
+    assert len( result ) == 2
+    ( new_a, new_b ) = result
+
+    # there should be no change, because prepare_lists() doesn't know how to merge a complex case like this
+    assert new_a == a
+    assert new_b == b
+
   def test_prepare_lists_with_link( self ):
     a = [ 'foo ', 'bar ', 'baz ', 'quux' ]
     b = [ 'foo ', '<a href="whee">', 'bar ', 'baz', '</a> ', 'quux' ]
@@ -247,6 +269,14 @@ class Test_html_differ( object ):
 
     assert result == 'foo <del class="diff modified">bar baz </del><ins class="diff modified"><i>bar whee baz</i> </ins>quux'
 
+  def test_diff_lists_with_italics_twice( self ):
+    a = [ 'foo ', 'bar ', 'baz ', 'quux ', '<i>foo</i>' ]
+    b = [ 'foo ', 'bar ', 'baz ', 'quux ', '<i>whee</i>', '<i>foo</i>' ]
+
+    result = self.differ.diff_lists( a, b )
+
+    assert result == 'foo bar baz quux <ins class="diff"><i>whee</i></ins><i>foo</i>'
+
   def test_diff_lists_with_link( self ):
     a = [ 'foo ', 'bar baz ', 'quux' ]
     b = [ 'foo ', '<a href="whee">bar baz</a> ', 'quux' ]