message: imgproc(hdr): fix bounds check in HdrDecoder::checkSignature()
diff: @@ -102,8 +102,12 @@ bool HdrDecoder::readData(Mat& _img)
  bool HdrDecoder::checkSignature( const String& signature ) const
  {
  if (signature.size() >= m_signature.size() &&
  - (!memcmp(signature.c_str(), m_signature.c_str(), m_signature.size()) ||
  - !memcmp(signature.c_str(), m_signature_alt.c_str(), m_signature_alt.size())))
  + 0 == memcmp(signature.c_str(), m_signature.c_str(), m_signature.size())
  + )
  + return true;
  + if (signature.size() >= m_signature_alt.size() &&
  + 0 == memcmp(signature.c_str(), m_signature_alt.c_str(), m_signature_alt.size())
  + )
  return true;
  return false;
  }
  