ADDITIONAL SYSTEM INFORMATION :
$ uname -a
Linux seneca 5.4.0-31-generic #35-Ubuntu SMP Thu May 7 20:20:34 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
$ java -version
openjdk version "14.0.1" 2020-04-14
OpenJDK Runtime Environment AdoptOpenJDK (build 14.0.1+7)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 14.0.1+7, mixed mode, sharing)


A DESCRIPTION OF THE PROBLEM :
An input stream provided to JavaShellToolBuilder isn't used in Java 14, confirmed working with Java 11

REGRESSION : Last worked in version 11.0.7

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Launch the provided source code, e.g. like this: "java JShellBug.java"


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
On system out the usage of the provided input stream should be reported on System.out
ACTUAL -
With java 14 the "read" method of the provided input stream is never called.

---------- BEGIN SOURCE ----------
// https://bugs.openjdk.java.net/browse/JDK-8246353?jql=%20Subcomponent%20%3D%20jshell%20and%20resolution%20is%20EMPTY%20ORDER%20BY%20created%20DESC
import jdk.jshell.tool.JavaShellToolBuilder;
import java.io.*;

/*
** The provided input stream is not used with java 14.0.1
**/
public class JShellBug {

    public static void main(String[] args) throws Exception {
       final InputStream input = new InputStream() {
                
           public int read() throws IOException {
               System.out.println("READ CALLED");
               Thread.dumpStack();
               return System.in.read();
           }
                
       };
       if (args.length == 0) {
          JavaShellToolBuilder.builder().in(input, null).run();
       } else {
          JavaShellToolBuilder.builder().in(input, input).run();
       }
    }
    
}
---------- END SOURCE ----------

FREQUENCY : always