fix bisection bug

1 files changed, 8 insertions, 10 deletions

diff --git a/tools/bisect_pair.py b/tools/bisect_pair.py
index 3b880b28..8eea0d61 100644
--- a/tools/bisect_pair.py
+++ b/tools/bisect_pair.py
@@ -47,14 +47,12 @@ if len(curr) > 0:
   chunks.append(curr)
 
 # Bisect both sides of the span, until we have a single chunk
-low = 0
 high = len(chunks)
 
 print 'beginning bisection, %d chunks' % high
 
-while high-low > 2:
-  mid = (low + high)/2
-  print '  current status: %d - %d - %d' % (low, mid, high)
+for mid in range(high):
+  print '  current: %d' % mid
   # Take chunks from the middle and on. This is important because the eliminator removes variables, so starting from the beginning will add errors
   curr_diff = '\n'.join(map(lambda parts: '\n'.join(parts), chunks[mid:])) + '\n'
   difff = open('diff.diff', 'w')
@@ -64,11 +62,11 @@ while high-low > 2:
   Popen(['patch', 'middle', 'diff.diff'], stdout=PIPE, stderr=PIPE).communicate()
   result = run_js('middle', stderr=PIPE)
   if result == left_result:
-    high = mid+1
-  else:
-    low = mid
+    print 'found where it starts to work: %d' % mid
+    found = mid
+    break
 
-critical = '\n'.join(chunks[low]) + '\n'
+critical = '\n'.join(chunks[found-1]) + '\n'
 
 c = open('critical.diff', 'w')
 c.write(critical)
@@ -76,8 +74,8 @@ c.close()
 print 'sanity check'
 shutil.copy('middle', 'middle2')
 Popen(['patch', 'middle2', 'critical.diff'], stdout=PIPE, stderr=PIPE).communicate()
-assert run_js('middle', stderr=PIPE) == left_result
-assert run_js('middle2', stderr=PIPE) != left_result
+assert run_js('middle', stderr=PIPE) == left_result, 'middle was expected %s' % left_result
+assert run_js('middle2', stderr=PIPE) != left_result, 'middle2 was expected NOT %s' % left_result
 
 print 'middle is like left, middle2 is like right, critical.diff is the difference that matters,'
 print critical