Merge "Consider 200 response with "Content-length <= 4" to not be a captive portal."

            // is needed (i.e. can't browse a 204).  This could be the result of an HTTP

            // proxy server.

            if (httpResponseCode == 200) {

                long contentLength = urlConnection.getContentLengthLong();

                if (probeType == ValidationProbeEvent.PROBE_PAC) {

                    validationLog(

                            probeType, url, "PAC fetch 200 response interpreted as 204 response.");

                    httpResponseCode = CaptivePortalProbeResult.SUCCESS_CODE;

                } else if (urlConnection.getContentLengthLong() == 0) {

                    // Consider 200 response with "Content-length=0" to not be a captive portal.

                    // There's no point in considering this a captive portal as the user cannot

                    // sign-in to an empty page. Probably the result of a broken transparent proxy.

                    // See http://b/9972012.

                    validationLog(probeType, url,

                            "200 response with Content-length=0 interpreted as 204 response.");

                    httpResponseCode = CaptivePortalProbeResult.SUCCESS_CODE;

                } else if (urlConnection.getContentLengthLong() == -1) {

                    // When no Content-length (default value == -1), attempt to read a byte from the

                    // response. Do not use available() as it is unreliable. See http://b/33498325.

                } else if (contentLength == -1) {

                    // When no Content-length (default value == -1), attempt to read a byte

                    // from the response. Do not use available() as it is unreliable.

                    // See http://b/33498325.

                    if (urlConnection.getInputStream().read() == -1) {

                        validationLog(

                                probeType, url, "Empty 200 response interpreted as 204 response.");

                        httpResponseCode = CaptivePortalProbeResult.SUCCESS_CODE;

                    }

                        validationLog(probeType, url,

                                "Empty 200 response interpreted as failed response.");

                        httpResponseCode = CaptivePortalProbeResult.FAILED_CODE;

                    }

                } else if (contentLength <= 4) {

                    // Consider 200 response with "Content-length <= 4" to not be a captive

                    // portal. There's no point in considering this a captive portal as the

                    // user cannot sign-in to an empty page. Probably the result of a broken

                    // transparent proxy. See http://b/9972012 and http://b/122999481.

                    validationLog(probeType, url, "200 response with Content-length <= 4"

                            + " interpreted as failed response.");

                    httpResponseCode = CaptivePortalProbeResult.FAILED_CODE;

                }

            }

        } catch (IOException e) {