Re: NSProtocolChecker doesn't forward messages

[Richard Frith-Macdonald]

On 25 Apr 2004, at 03:37, J.F.Costa wrote:

> Hi, everybody.
>
>         NSProtocolChecker instances don't forward the messages that are in
> it's protocol. Here is NSProtocolChecker's forwarding method:
>
>
> - (void) forwardInvocation: (NSInvocation*)anInvocation
> {
>   unsigned int  length;
>   void          *buffer;
>
>   if ((struct objc_method_description *)NULL
>     != [self methodDescriptionForSelector: [anInvocation selector]])
>     [[NSException exceptionWithName: NSInvalidArgumentException
>                   reason: @"Method not declared in current protocol"
>                   userInfo: nil] raise];
>
>   [anInvocation invokeWithTarget: _myTarget];
>
>   length = [[anInvocation methodSignature] methodReturnLength];
>   buffer = (void *)malloc(length);
>   [anInvocation getReturnValue: buffer];
>
>   if (0 == strcmp([[anInvocation methodSignature] methodReturnType],
>                   [[anInvocation methodSignatureForSelector:
>                                   @selector(init: )] methodReturnType]) )
>     {
>       if (((id)buffer) == _myTarget)
>         {
>           buffer = self;
>           [anInvocation setReturnValue: buffer];
>         }
>     }
>
>   return;
> }
>
>         Notice that the comparison symbol in the protocol check is wrong, it
> should be '=='. Besides that, there is something wrong with the
> condition in the second 'if', because the former segfaults. What is
> the correct condition?

I looked at the source for this class, and it appears nobody has ever 
used/tested it
since it was written in 1998!  It looks completely broken, with a 
couple of memory
leaks, missing method implementations, extra bogus code etc.

I have placed a rewritten version in CVS, which should actually work 
now I hope.