Pre-extend the ISA hash in Perl_mro_get_linear_isa().

Perl · Aug 23, 2021 · 009b864 · 009b864
1 parent ded520d
commit 009b864
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/mro_core.c b/mro_core.c
@@ -440,11 +440,16 @@ Perl_mro_get_linear_isa(pTHX_ HV *stash)
     if (!meta->isa) {
             HV *const isa_hash = newHV();
             /* Linearisation didn't build it for us, so do it here.  */
+            I32 count = AvFILLp(isa) + 1;
             SV *const *svp = AvARRAY(isa);
-            SV *const *const svp_end = svp + AvFILLp(isa) + 1;
+            SV *const *const svp_end = svp + count;
             const HEK *canon_name = HvENAME_HEK(stash);
             if (!canon_name) canon_name = HvNAME_HEK(stash);
 
+            if (count > PERL_HASH_DEFAULT_HvMAX) {
+                hv_ksplit(isa_hash, count);
+            }
+
             while (svp < svp_end) {
                 (void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0);
             }