old_contents: #!/usr/bin/env python
  from __future__ import (absolute_import, division, print_function)
  __metaclass__ = type
  
  import os
  import sys
  
  
  def main():
      for path in sys.argv[1:] or sys.stdin.read().splitlines():
          if not os.path.islink(path.rstrip(os.path.sep)):
              continue
  
          if not os.path.exists(path):
              print('%s: broken symlinks are not allowed' % path)
  
          if path.endswith(os.path.sep):
              print('%s: symlinks to directories are not allowed' % path)
  
  
  if __name__ == '__main__':
      main()
  
new_contents: #!/usr/bin/env python
  from __future__ import (absolute_import, division, print_function)
  __metaclass__ = type
  
  import os
  import sys
  
  
  def main():
      root_dir = os.getcwd() + os.path.sep
  
      for path in sys.argv[1:] or sys.stdin.read().splitlines():
          if not os.path.islink(path.rstrip(os.path.sep)):
              continue
  
          if not os.path.exists(path):
              print('%s: broken symlinks are not allowed' % path)
              continue
  
          if path.endswith(os.path.sep):
              print('%s: symlinks to directories are not allowed' % path)
              continue
  
          real_path = os.path.realpath(path)
  
          if not real_path.startswith(root_dir):
              print('%s: symlinks outside content tree are not allowed: %s' % (path, os.path.relpath(real_path, os.path.dirname(path))))
              continue
  
  
  if __name__ == '__main__':
      main()
  
subject: Add out-of-tree check to symlinks sanity test.