diff -r c6237edff631 Lib/tokenize.py
--- a/Lib/tokenize.py	Sat Nov 03 18:29:31 2012 +0200
+++ b/Lib/tokenize.py	Sat Nov 03 20:47:40 2012 -0400
@@ -226,10 +226,16 @@
         self.prev_col = 0
         self.encoding = None
 
-    def add_whitespace(self, start):
+    def add_whitespace(self, start, supply_line_continuation):
         row, col = start
-        assert row <= self.prev_row
         col_offset = col - self.prev_col
+        # Nearly all newlines are handled by the NL and NEWLINE tokens,
+        # but explicit line continuations are not, so they're handled here.
+        if row > self.prev_row:  
+            row_offset = row - self.prev_row
+            if supply_line_continuation:
+                self.tokens.append(" \\\n" * row_offset)
+            col_offset = col  # Recalculate the column offset from the start of our new line        
         if col_offset:
             self.tokens.append(" " * col_offset)
 
@@ -242,7 +248,8 @@
             if tok_type == ENCODING:
                 self.encoding = token
                 continue
-            self.add_whitespace(start)
+            self.add_whitespace(start,
+                                supply_line_continuation=(tok_type!=ENDMARKER) )
             self.tokens.append(token)
             self.prev_row, self.prev_col = end
             if tok_type in (NEWLINE, NL):