crash: java.lang.AssertionError at com.sun.tools.javac.code.Types.containedBy(Types.java:792)

FULL PRODUCT VERSION :
J2SE(TM) Development Kit 5.0 Update 1 (jdk 1.5.0.01)

ADDITIONAL OS VERSION INFORMATION :
Suse 9.2 professionnal (kernel 2.6.8)

A DESCRIPTION OF THE PROBLEM :
import java.util.*;

public class Generic {

public <K> TreeMap<K,K> essai(K type) {
TreeMap<K,K> treeMap = new TreeMap<K,K>();
return treeMap;
}

public static void main(String args[]) {
Generic generic = new Generic();

//et ci-dessous c'est le drame
TreeMap<?,?> treeMap = generic.essai(null);

}
}

------------------------------------------------------------------------

Try to compile the program above

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
import java.util.*;

public class Generic {

public <K> TreeMap<K,K> essai(K type) {
TreeMap<K,K> treeMap = new TreeMap<K,K>();
return treeMap;
}

public static void main(String args[]) {
Generic generic = new Generic();

//et ci-dessous c'est le drame
TreeMap<?,?> treeMap = generic.essai(null);

}
}

------------------------------------------------------------------------

Try to compile the program above

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I don't know, but the compiler said me it crashed and send you this report of bug
ACTUAL -
Compiler crashes

ERROR MESSAGES/STACK TRACES THAT OCCUR :
hibounds=java.lang.Object
An exception has occurred in the compiler (1.5.0-rc). Please file a bug at the Java Developer Connection (http://java.sun.com/webapps/bugreport) after checking the Bug Parade for duplicates. Include your program and the following diagnostic in your report. Thank you.
java.lang.AssertionError
        at com.sun.tools.javac.code.Types.containedBy(Types.java:792)
        at com.sun.tools.javac.code.Types$ContainsTypeFcn.visitArgumentType(Types.java:871)
        at com.sun.tools.javac.code.Type$ArgumentType.accept(Type.java:358)
        at com.sun.tools.javac.code.Types$ContainsTypeFcn.containsType(Types.java:851)
        at com.sun.tools.javac.code.Types.containsType(Types.java:841)
        at com.sun.tools.javac.code.Types.containsType(Types.java:811)
        at com.sun.tools.javac.code.Types$IsSubTypeFcn.visitClassType(Types.java:421)
        at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:473)
        at com.sun.tools.javac.code.Types$IsSubTypeFcn.isSubType(Types.java:344)
        at com.sun.tools.javac.code.Types.isSubType(Types.java:327)
        at com.sun.tools.javac.comp.Infer.instantiateExpr(Infer.java:237)
        at com.sun.tools.javac.comp.Check.instantiatePoly(Check.java:354)
        at com.sun.tools.javac.comp.Check.checkType(Check.java:322)
        at com.sun.tools.javac.comp.Attr.check(Attr.java:140)
        at com.sun.tools.javac.comp.Attr.visitApply(Attr.java:1110)
        at com.sun.tools.javac.tree.Tree$Apply.accept(Tree.java:819)
        at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:256)
        at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:271)
        at com.sun.tools.javac.comp.Attr.visitVarDef(Attr.java:531)
        at com.sun.tools.javac.tree.Tree$VarDef.accept(Tree.java:511)
        at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:256)
        at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:291)
        at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:307)
        at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:561)
        at com.sun.tools.javac.tree.Tree$Block.accept(Tree.java:540)
        at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:256)
        at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:291)
        at com.sun.tools.javac.comp.Attr.visitMethodDef(Attr.java:494)
        at com.sun.tools.javac.tree.Tree$MethodDef.accept(Tree.java:482)
        at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:256)
        at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:291)
        at com.sun.tools.javac.comp.Attr.attribClassBody(Attr.java:2424)
        at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:2357)
        at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:2306)
        at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:410)
        at com.sun.tools.javac.main.Main.compile(Main.java:592)
        at com.sun.tools.javac.main.Main.compile(Main.java:544)
        at com.sun.tools.javac.Main.compile(Main.java:58)
        at com.sun.tools.javac.Main.main(Main.java:48)


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.*;

public class Generic {

public <K> TreeMap<K,K> essai(K type) {
TreeMap<K,K> treeMap = new TreeMap<K,K>();
return treeMap;
}

public static void main(String args[]) {
Generic generic = new Generic();

//et ci-dessous c'est le drame
TreeMap<?,?> treeMap = generic.essai(null);

}
}

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

CUSTOMER SUBMITTED WORKAROUND :
import java.util.*;

public class Generic {

public <K> TreeMap<K,K> essai(K type) {
TreeMap<K,K> treeMap = new TreeMap<K,K>();
return treeMap;
}

public static void main(String args[]) {
Generic generic = new Generic();

//use whatever but not wildcard type even if it doesn't mean the same
TreeMap<Object,Object> treeMap = generic.essai(null);

}
}
###@###.### 2005-1-07 18:48:49 GMT