Merge "Skip verifying the partition with no changed blocks." into nyc-dev

  def WriteVerifyScript(self, script, touched_blocks_only=False):

    partition = self.partition

    # full OTA

    if not self.src:

      script.Print("Image %s will be patched unconditionally." % (partition,))

    # incremental OTA

    else:

      if touched_blocks_only and self.version >= 3:

        ranges = self.touched_src_ranges

      else:

        ranges = self.src.care_map.subtract(self.src.clobbered_blocks)

        expected_sha1 = self.src.TotalSha1()

      # No blocks to be checked, skipping.

      if not ranges:

        return

      ranges_str = ranges.to_string_raw()

      if self.version >= 4:

        script.AppendExtra(('if (range_sha1("%s", "%s") == "%s" || '