[GROOVY-5630] Java stub generator generates wrong cast for return value of generic method

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.8.7
• Fix Version/s: 2.0.4, 2.1.0-beta-1, 1.8.9
• Component/s: Stub generator / Joint compiler
• Assignee: Guillaume Sauthier
• Reporter: Peter Niederwieser
• Created: 25/Jul/12 17:18
• Updated: 21/Sep/12 16:58
• Resolved: 18/Sep/12 06:32

Description

From org/gradle/util/HelperUtil.groovy:

class HelperUtil {
    ...
    static <T extends Task> T createTask(Class<T> type) {
        ...
    }
    ...
}

Generated method stub in Groovy 1.8.6:

public static <T extends org.gradle.api.Task> T createTask(java.lang.Class<T> type) { return (T)null;}

This stub compiles fine.

Generated method stub in Groovy 1.8.7:

public static <T extends org.gradle.api.Task> T createTask(java.lang.Class<T> type) { return (org.gradle.api.Task)null;}

This stub gives the following compile error:

/swd/prj/gradle/subprojects/core/build/tmp/groovy-java-stubs/org/gradle/util/HelperUtil.java:22: error: incompatible types
public static <T extends org.gradle.api.Task> T createTask(java.lang.Class<T> type) { return (org.gradle.api.Task)null;}
                                                                                             ^
  required: T
  found:    Task
  where T is a type-variable:
    T extends Task declared in method <T>createTask(Class<T>)