Tells an SV to use C<ptr> to find its string value. Normally the
string is stored inside the SV but sv_usepvn allows the SV to use an
outside string. The C<ptr> should point to memory that was allocated
-by C<malloc>. The string length, C<len>, must be supplied. By default
+by C<malloc>. It must be the start of a mallocked block
+of memory, and not a pointer to the middle of it. The
+string length, C<len>, must be supplied. By default
this function will realloc (i.e. move) the memory pointed to by C<ptr>,
so that pointer should not be freed or used by the programmer after
giving it to sv_usepvn, and neither should any pointers from "behind"
* back into v-string notation and then let the
* vectorize happen normally
*/
- if (sv_derived_from(vecsv, "version") && SvROK(vecsv)) {
+ if (sv_isobject(vecsv) && sv_derived_from(vecsv, "version")) {
char *version = savesvpv(vecsv);
if ( hv_exists(MUTABLE_HV(SvRV(vecsv)), "alpha", 5 ) ) {
Perl_warner(aTHX_ packWARN(WARN_INTERNAL),