Strange error message referring to nonexistant String, upon type error

Name: js151677 Date: 08/27/2004


FULL PRODUCT VERSION :
java version "1.4.2_03"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_03-b02)
Java HotSpot(TM) Client VM (build 1.4.2_03-b02, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
Attempting to compile the following test case as test.java:

public class test {
  private static int x = (new Object() + 1) + 1;
}

gives the expected error message for the addition of an Object and an int, but then also mysteriously complains about "incompatible types: found:java.lang.String(), required: int". Further experimentation suggests that the entire right-hand side is being interpreted as a String being assigned to the int x.

It appears that the second plus sign coerces its left-hand-side into a String once its type cannot be determined, which rather breaks expectations - while adding an int is a valid operation for Strings, it is also valid, and more common, for other ints. Replacing the second plus sign with a different mathematical operator produces only one error, as expected.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Paste the following code to a new file 'test.java':

public class test {
  private static int x = (new Object() + 1) + 1;
}

and attempt to compile.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
test.java:2: operator + cannot be applied to java.lang.Object,int
  private static int x = (new Object() + 1) + 1;
                                       ^
1 error
ACTUAL -
test.java:2: operator + cannot be applied to java.lang.Object,int
  private static int x = (new Object() + 1) + 1;
                                       ^
test.java:2: incompatible types
found : java.lang.String
required: int
  private static int x = (new Object() + 1) + 1;
                                            ^
2 errors

ERROR MESSAGES/STACK TRACES THAT OCCUR :
See above (since expected and actual result pertain to error messages)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class test {
  private static int x = (new Object() + 1) + 1;
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
None (besides the obvious "don't write buggy code").
(Incident Review ID: 301002)
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