ADDITIONAL SYSTEM INFORMATION :
windows 10

A DESCRIPTION OF THE PROBLEM :
When I use String a = new String("1") + new String("2"); then String b = "12"; when I compare a and b, I find that the output is false, then I try to put the above The splicing string changes the value, and the other changes are no problem. They are all true. Only when "12" returns false here, and when I change the version back to java8, there is no such problem.

REGRESSION : Last worked in version 8u202

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
public static void main(String[] args) {
String a = new String("1") + new String("2");
a.intern();
a.intern();
String b = "12";
System.out.println(a == b);

}

ACTUAL -
false

---------- BEGIN SOURCE ----------
public static void main(String[] args) {
String a = new String("1") + new String("2");
a.intern();
a.intern();
String b = "12";
System.out.println(a == b);

}
---------- END SOURCE ----------

FREQUENCY : always