sorter_alloc_buf(ctx);
if (in->flags & SBF_CUSTOM_PRESORT)
{
+ /*
+ * The trick with automatic joining, which we use for the normal presorter,
+ * is not necessary with the custom presorter, because the custom presorter
+ * is never called in the middle of the sorted data.
+ */
struct fastbuf *f = sbuck_write(out);
out->runs++;
return ctx->custom_presort(f, ctx->big_buf, ctx->big_buf_size);