[Fluxus] string leak!

[gabor papp]

while checking out the path/string issue that kassen brought up i found 
our string handling a bit strange. the memory usage of the following 
script increases about 30 megabytes in 2 minutes on my computer. i 
generate a long string which i use in (load-texture) to force the scheme 
string to c conversion.

(clear)

(define (rnd-str n)
   (build-string n (lambda (x) (integer->char (+ 97 (random 26))))))

(every-frame
     (begin
         (load-texture (rnd-str 16384))
         (collect-garbage)))

StringFromScheme looks like this:

string SchemeHelper::StringFromScheme(Scheme_Object *ob)
{
     char *ret = NULL;
     MZ_GC_DECL_REG(2);
     MZ_GC_VAR_IN_REG(0, ob);
     MZ_GC_VAR_IN_REG(1, ret);
     MZ_GC_REG();
     ret = scheme_utf8_encode_to_buffer(SCHEME_CHAR_STR_VAL(ob), 
SCHEME_CHAR_STRLEN_VAL(ob), NULL, 0);
     MZ_GC_UNREG();
     return string(ret);
}

first i thought it was strange to register a char* buffer with the 
garbage collector, but after reading the docs it may seem fine. what do 
you think? can you reproduce the leaking? or am i overlooking something?

this would also explain the (pdata-map) leak, since it uses strings to 
pass the pdata type in pdata-set!.

best,
gabor