Incorrect merging of frames

Consider the following Jasmin code:

.class public SimpleDecoherence
.super java/lang/Object

.method public static foo(J)V
    .limit stack  1
    .limit locals 2

    iconst_0
    ifne skip

    iconst_0
    istore_1

skip:

    return
.end method

The following test case (using ASM 3.1) reads the compiled class, writes it
with COMPUTE_FRAMES, rereads and prints.

ClassReader cr = new ClassReader("SimpleDecoherence");
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
cr.accept(cw, 0);
ClassReader cr2 = new ClassReader(cw.toByteArray());
TraceClassVisitor tcv = new TraceClassVisitor(new PrintWriter(System.out));
cr2.accept(tcv, 0);

Here is the result:

  public static foo(J)V
   FRAME FULL [] []
    ICONST_0
    IFNE L0
    ICONST_0
    ISTORE 1
   L0
   FRAME FULL [J] []
    RETURN
    MAXSTACK = 1
    MAXLOCALS = 2

In the second FRAME, the parameter is still "J T", while it should be "T T". I
tried to fix this as follows in org.objectweb.asm.Frame (near line 930, the
third t2 compairson):

case Opcodes.ISTORE:
case Opcodes.FSTORE:
case Opcodes.ASTORE:
    t1 = pop();
    set(arg, t1);
    if (arg > 0) {
        t2 = get(arg - 1);
        // if t2 is of kind STACK or LOCAL we cannot know its size!
        if (t2 == LONG || t2 == DOUBLE || t2 == (LOCAL | 0)) {
            set(arg - 1, TOP);
        }
    }
break;

and similar for LSTORE/DSTORE. The result is now:

  public static foo(J)V
   FRAME FULL [] []
    ICONST_0
    IFNE L0
    ICONST_0
    ISTORE 1
   L0
   FRAME FULL [] []
    RETURN
    MAXSTACK = 1
    MAXLOCALS = 2

However, changing descriptor of foo to (I)V results in variable 0 turned to T
as well. I guess that's why the comment about not knowing the size is there.
Unfortunately, I am not sufficiently familiar with the implementation to
provide a real fix... (Don't really understand why t2 isn't just LONG there.)

NOTE: technically, the code (after COMPUTE_FRAMES) passes verification, but an
incorrect frame is still a problem for code that analyzes frames.