Do not actually remove trees when test bisect in dry-run mode

tools/auto_bisect/bisect_perf_regression_test.py

Index: tools/auto_bisect/bisect_perf_regression_test.py
diff --git a/tools/auto_bisect/bisect_perf_regression_test.py b/tools/auto_bisect/bisect_perf_regression_test.py
index d25992d18adf04272348130d85d096b1b2374aa0..80f9e0930871a11a3052739981d4191943c402a0 100644
--- a/tools/auto_bisect/bisect_perf_regression_test.py
+++ b/tools/auto_bisect/bisect_perf_regression_test.py
@@ -4,6 +4,7 @@
 
 import os
 import re
+import shutil
 import unittest
 
 import bisect_perf_regression
@@ -246,12 +247,16 @@ class BisectPerfRegressionTest(unittest.TestCase):
     This serves as a smoke test to catch errors in the basic execution of the
     script.
     """
+    # Disable rmtree to avoid deleting local trees.
+    old_rmtree = shutil.rmtree
+    shutil.rmtree = lambda path, onerror: None

[ojan, 2014/09/19 17:42:52]

I typically do this in a try/finally so you can be sure shutil.rmtree gets reset
in case the test throws an error. That way this test won't affect the running of
other tests.

old_rmtree = shutil.rmtree
try:
  shutil.rmtree = lambda path, onerror: None
  # THE REST OF THE TEST CODE HERE
finally:
  shutil.rmtree = old_rmtree

[Sergiy Byelozyorov, 2014/09/22 20:04:15]

Done.

     bisect_instance = _GetBisectPerformanceMetricsInstance()
     results = bisect_instance.Run(bisect_instance.opts.command,
                                   bisect_instance.opts.bad_revision,
                                   bisect_instance.opts.good_revision,
                                   bisect_instance.opts.metric)
     bisect_instance.FormatAndPrintResults(results)
+    shutil.rmtree = old_rmtree
 
   def testGetCommitPosition(self):
     bisect_instance = _GetBisectPerformanceMetricsInstance()