Use system command to unzip binaries from zip file on Mac OS

tools/bisect-builds.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Snapshot Build Bisect Tool
 
 This script bisects a snapshot archive using binary search. It starts at
 a bad revision (it will try to guess HEAD) and asks for a last known-good
 revision. It will then binary search across this revision range by downloading,
@@ skipping 434 matching lines @@
         self.good_revision = FixChromiumRevForBlink(revlist,
                                                     revlist_all,
                                                     self,
                                                     self.good_revision)
         self.bad_revision = FixChromiumRevForBlink(revlist,
                                                    revlist_all,
                                                    self,
                                                    self.bad_revision)
     return revlist
 
+
+def IsMac():
+  return sys.platform.startswith('darwin')
+
+
 def UnzipFilenameToDir(filename, directory):
   """Unzip |filename| to |directory|."""
   cwd = os.getcwd()
   if not os.path.isabs(filename):
     filename = os.path.join(cwd, filename)
-  zf = zipfile.ZipFile(filename)
   # Make base.
   if not os.path.isdir(directory):
     os.mkdir(directory)
   os.chdir(directory)
+
+  # The Python ZipFile does not support symbolic links, which makes it
+  # unsuitable for Mac builds. so use ditto instead.
+  if IsMac():
+    unzip_cmd = ['ditto', '-x', '-k', filename, '.']
+    proc = subprocess.Popen(unzip_cmd, bufsize=0, stdout=subprocess.PIPE,
+                            stderr=subprocess.PIPE)
+    proc.communicate()
+    os.chdir(cwd)
+    return
+
+  zf = zipfile.ZipFile(filename)
   # Extract files.
   for info in zf.infolist():
     name = info.filename
     if name.endswith('/'):  # dir
       if not os.path.isdir(name):
         os.makedirs(name)
     else:  # file
       directory = os.path.dirname(name)
       if not os.path.isdir(directory):
         os.makedirs(directory)
@@ skipping 690 matching lines @@
     if min_blink_rev != max_blink_rev:
       print ('NOTE: There is a Blink roll in the range, '
              'you might also want to do a Blink bisect.')
 
     print 'CHANGELOG URL:'
     PrintChangeLog(min_chromium_rev, max_chromium_rev)
 
 
 if __name__ == '__main__':
   sys.exit(main())