On Thu, 23 May 2002, Daniel Grunblatt wrote:
>
> On Wed, 22 May 2002, Sean O'Rourke wrote:
>
> > that pack() can't handle null bytes makes it a bit more complicated (and
> Exactly how do you want it to handle null bytes?
Nevermind -- sorry 'bout that. There's a little wierdness in there, but
it isn't because of nulls -- I just spaced out reading the pack docs.
The strangeness is with the 4-argument version of pack(), which doesn't
extend its first argument if the pack destination goes past the end of the
string. So you get this:
set S0, ""
set I0, 42
pack S0, 4, I0, 0
length I1, S0 # is 0
pack S0, 4, I0
length I1, S0 # is 4
pack S0, 4, I0, 10000 # is segv
which is completely unrelated to nulls, but still strange. I was thrown
off by this result when trying to use the offset version of pack. I
attached a patch that (I think) does something with less startle value.
/s
RCS file: /cvs/public/parrot/core.ops,v
retrieving revision 1.143
diff -u -p -r1.143 core.ops
--- core.ops 20 May 2002 17:52:28 -0000 1.143
+++ core.ops 23 May 2002 15:03:31 -0000
@@ -1957,11 +1957,17 @@ inline op pack(inout STR, in INT, in STR
inline op pack(inout STR, in INT, in INT, in INT) {
char *c = (char *)&$3, *n;
STRING *s;
+ INTVAL ln;
const char *t;
int i;
s = string_make(interpreter, c, (UINTVAL)$2, NULL, 0, NULL);
s->flags |= BUFFER_neonate_FLAG;
+ ln = string_length($1);
+ assert($4 <= ln);
+ if (ln < $4 + $2)
+ string_grow(interpreter, $1, $4 + $2 - ln)
+
/* XXX this is EVIL, use string_replace */
n = $1->bufstart;
t = string_to_cstring(interpreter, (s));
