--- a/mercurial/pure/bdiff.py	Mon Jan 25 00:05:22 2010 -0600
+++ b/mercurial/pure/bdiff.py	Mon Jan 25 00:05:27 2010 -0600
@@ -33,13 +33,15 @@
         a2end = a2 + l2
         b2end = b2 + l2
         if a1end == a2:
-            while a1end+shift < a2end and a[a1end+shift] == b[b1end+shift]:
+            while (a1end + shift < a2end and
+                   a[a1end + shift] == b[b1end + shift]):
                 shift += 1
         elif b1end == b2:
-            while b1end+shift < b2end and a[a1end+shift] == b[b1end+shift]:
+            while (b1end + shift < b2end and
+                   a[a1end + shift] == b[b1end + shift]):
                 shift += 1
-        yield a1, b1, l1+shift
-        prev = a2+shift, b2+shift, l2-shift
+        yield a1, b1, l1 + shift
+        prev = a2 + shift, b2 + shift, l2 - shift
     yield prev
 
 def bdiff(a, b):