FULL PRODUCT VERSION :
java version "1.8.0_172-ea"
Java(TM) SE Runtime Environment (build 1.8.0_172-ea-b03)
Java HotSpot(TM) 64-Bit Server VM (build 25.172-b03, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Darwin hostname 17.4.0 Darwin Kernel Version 17.4.0: Sun Dec 17 09:19:54 PST 2017; root:xnu-4570.41.2~1/RELEASE_X86_64 x86_64

EXTRA RELEVANT SYSTEM CONFIGURATION :
running squid proxy in local docker instance

A DESCRIPTION OF THE PROBLEM :
Tunneling a HTTPS request through a proxy that uses authorization fails unless a http request is performed first.

using a HTTP backend works fine. It also seems to populate a cache that is used for HTTPS, so performing a HTTP request first seems to enable HTTPS.

REGRESSION. Last worked in version 8u151

ADDITIONAL REGRESSION INFORMATION:
last working version:
java version "1.8.0_102"
Java(TM) SE Runtime Environment (build 1.8.0_102-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.102-b14, mixed mode)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1) start a docker container with a local squid proxy w/ auth
docker run -e SQUID_USERNAME=foo -e SQUID_PASSWORD=bar -p 3128:3128 robhaswell/squid-authenticated

2) execute the provided java program

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
the output should look like this (the first request should be successful and the password should be requested in the initial https call)

=== BEGIN https ===
>>> requesting password
{
  "headers": {
    "Accept": "text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2",
    "Connection": "close",
    "Host": "httpbin.org",
    "User-Agent": "Java/1.8.0_102"
  }
}

=== END https ===
=== BEGIN http ===
{
  "headers": {
    "Accept": "text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2",
    "Cache-Control": "max-age=259200",
    "Connection": "close",
    "Host": "httpbin.org",
    "User-Agent": "Java/1.8.0_102"
  }
}

=== END http ===
=== BEGIN https ===
{
  "headers": {
    "Accept": "text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2",
    "Connection": "close",
    "Host": "httpbin.org",
    "User-Agent": "Java/1.8.0_102"
  }
}

=== END https ===
ACTUAL -
the initial HTTPS request fails and does call the Authenticator

=== BEGIN https ===
ERROR: Unable to tunnel through proxy. Proxy returns "HTTP/1.1 407 Proxy Authentication Required"
=== END https ===
=== BEGIN http ===
>>> requesting password
{
  "headers": {
    "Accept": "text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2",
    "Cache-Control": "max-age=259200",
    "Connection": "close",
    "Host": "httpbin.org",
    "User-Agent": "Java/1.8.0_172-ea"
  }
}

=== END http ===
=== BEGIN https ===
{
  "headers": {
    "Accept": "text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2",
    "Connection": "close",
    "Host": "httpbin.org",
    "User-Agent": "Java/1.8.0_172-ea"
  }
}

=== END https ===

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import static java.util.Arrays.asList;

import java.io.InputStream;
import java.net.Authenticator;
import java.net.PasswordAuthentication;
import java.net.URI;
import java.util.Scanner;

public class Sample
{
    public static void main( String[] args )
    {
        for ( String protocol : asList( "http", "https" ) )
        {
            System.setProperty( protocol + ".proxyHost", "localhost" );
            System.setProperty( protocol + ".proxyPort", "3128" );
        }

        Authenticator.setDefault( new Authenticator()
        {
            @Override
            protected PasswordAuthentication getPasswordAuthentication()
            {
                System.out.println( ">>> requesting password" );
                return new PasswordAuthentication( "foo", "bar".toCharArray() );
            }
        } );

        for ( String protocol : asList( "https", "http", "https" ) )
        {
            System.out.println( "=== BEGIN " + protocol + " ===" );

            try ( InputStream in = new URI( protocol, "httpbin.org", "/headers", null ).toURL().openStream() )
            {
                System.out.println( asString( in ) );
            }
            catch ( Exception e )
            {
                System.out.println( "ERROR: " + e.getMessage() );
            }

            System.out.println( "=== END " + protocol + " ===" );
        }
    }

    private static String asString( InputStream in )
    {
        try ( Scanner scanner = new Scanner( in ) )
        {
            scanner.useDelimiter( "\0" );
            return scanner.hasNext() ? scanner.next() : "";
        }
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
performing a HTTP request beforehand seems to create a state where subsequent request succeed but this requires code changes in existing applications and has other negative implications as well.