Bug 289307

Description Vilas Jagannath 2009-09-13 21:24:43 EDT

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.14) Gecko/2009090216 Ubuntu/9.04 (jaunty) Firefox/3.0.14
Build Identifier: M20080221-1800

When the infer generic type refactoring is applied to a program using the generic List type along with a complex class hierarchy, the refactoring incorrectly infers the generic type for one of the variables which leads to the program not compiling any more. Please look at the steps for more details on how to reproduce this bug.

Reproducible: Always

Steps to Reproduce:
1. Copy the following code into a java file called A.java:

import java.util.List;

class A implements B, D {
    public List m() {
        List l = null;
        A a = null;
        l.add(a.m());
        return l;
    }
}

interface D {
    public List m();
}

interface B extends C {
    public List m();
}

interface C {
    public List m();
}

2. Apply the infer generic type refactoring on the program (with default options).

3. The application of the refactoring leads to the program not compiling any more because the generic type for A.m().l is incorrectly inferred. Here is the resulting non compilable program:

import java.util.List;

class A implements B, D {
    public List<List> m() {
        List<List<List>> l = null;
        A a = null;
        l.add(a.m());
        return l;
    }
}

interface D {
    public List<List> m();
}

interface B extends C {
    public List<List> m();
}

interface C {
    public List<List> m();
}