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https://issues.apache.org/jira/browse/GROOVY-10625?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Eric Milles updated GROOVY-10625:
---------------------------------
Priority: Minor (was: Major)
> Issue in subtyping leads to unsound results
> -------------------------------------------
>
> Key: GROOVY-10625
> URL: https://issues.apache.org/jira/browse/GROOVY-10625
> Project: Groovy
> Issue Type: Bug
> Components: Static Type Checker
> Reporter: Thodoris Sotiropoulos
> Assignee: Eric Milles
> Priority: Minor
>
> I have the following program
> {code}
> class A<T> {
> T x;
> A(T x) {this.x = x;}
> A() {}
> }
> class B<T extends Object> extends A<T> {
> B(T x) {
> super(x);
> }
> B() {}
> T m() {
> A<T> x = new B<Object>("fd"); // Misses type error: B<Object> is not a
> subtype of A<T>
> return x.x;
> }
> }
> class Test {
> public static void main(String[] args) {
> Integer x = new B<Integer>().m();
> }
> }
> {code}
> h3. Actual behavior
> The above program contains a type error, but the compilers misses it. As a
> result, a ClassCastException happens at runtime:
> {code}
> Exception in thread "main"
> org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast
> object 'fd' with class 'java.lang.String' to class 'java.lang.Integer'
> at
> org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToNumber(DefaultTypeTransformation.java:180)
> at
> org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.continueCastOnNumber(DefaultTypeTransformation.java:295)
> at
> org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToType(DefaultTypeTransformation.java:252)
> at
> org.codehaus.groovy.vmplugin.v8.IndyInterface.fromCache(IndyInterface.java:318)
> at Test.main(test.groovy:25)
> {code}
> h3. Expected behaviour
> The compiler should not have type checked the assignment at line 17 and have
> produced an error message of the form: B<Object> cannot be converted into
> A<T>.
> Tested against master (commit: ee12bb52381e8f0583c61fc25d43de1f55b80a87)
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