-#ifdef PERL_MALLOC_WRAP
- static const char oom_array_extend[] =
- "Out of memory during array extend"; /* Duplicated in pp_hot.c */
-#endif
-
- if (AvALLOC(av)) {
-#if !defined(STRANGE_MALLOC) && !defined(MYMALLOC)
- MEM_SIZE bytes;
- IV itmp;
-#endif
-
-#ifdef MYMALLOC
- newmax = malloced_size((void*)AvALLOC(av))/sizeof(SV*) - 1;
+ if (*allocp) {
+
+#ifdef Perl_safesysmalloc_size
+ /* Whilst it would be quite possible to move this logic around
+ (as I did in the SV code), so as to set AvMAX(av) early,
+ based on calling Perl_safesysmalloc_size() immediately after
+ allocation, I'm not convinced that it is a great idea here.
+ In an array we have to loop round setting everything to
+ NULL, which means writing to memory, potentially lots
+ of it, whereas for the SV buffer case we don't touch the
+ "bonus" memory. So there there is no cost in telling the
+ world about it, whereas here we have to do work before we can
+ tell the world about it, and that work involves writing to
+ memory that might never be read. So, I feel, better to keep
+ the current lazy system of only writing to it if our caller
+ has a need for more space. NWC */
+ newmax = Perl_safesysmalloc_size((void*)*allocp) /
+ sizeof(const SV *) - 1;