FULL PRODUCT VERSION :
java version "1.7.0_02"
Java(TM) SE Runtime Environment (build 1.7.0_02-b13)
Java HotSpot(TM) Client VM (build 22.0-b10, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Windows XP Tablet PC Edition 2005 SP3 (probably irrelevant)

EXTRA RELEVANT SYSTEM CONFIGURATION :
Using Eclipse 3.7.2 (probably irrelevant)

A DESCRIPTION OF THE PROBLEM :
The following code:

public static class Item {
  public Long getID() { return null; }
}

public static void main(String[] args) {
  Item i = new Item();
  Long ID = (i==null) ? 0L : i.getID();
  System.out.println(ID);
}

produces a java.lang.NullPointerException in the line starting with "Long ID = ...". This seems to be due to the fact that the ternary operation is trying to cast the null value returned from i.getID() to a long (lower case) to match the type of 0L rather than casting 0L to a Long. This, in my opinion, seems like a bug as the equivalent if...else statement does not show this behavior. This happens with Integer and Boolean as well. Switching the result cases (i!=null) does not fix the problem (i.e. first result case does not take type-precedence over second one).

Explicitly casting 0L to Long instead by changing the line to:

  Long ID = (i==null) ? (Long) 0L : i.getID();

fixes the problem.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run code:

public static class Item {
  public Long getID() { return null; }
}

public static void main(String[] args) {
  Item i = new Item();
  Long ID = (i==null) ? 0L : i.getID();
  System.out.println(ID);
}

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
assign null to ID and print it
ACTUAL -
throws java.lang.NullPointerException in line starting with "Long ID = ..."

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception in thread "main" java.lang.NullPointerException at Main.main (line starting with "Long ID = ...")

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class Main {

  public static class Item {
    public Long getID() { return null; }
  }

  public static void main(String[] args) {
    Item i = new Item();
    Long ID = (i==null) ? 0L : i.getID();
    System.out.println(ID);
  }

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

CUSTOMER SUBMITTED WORKAROUND :
Explicitly cast result cases to "broader" type:
  Long ID = (i==null) ? (Long) 0L : i.getID();