+ if (skipping) continue;
+
+ while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
+ {
+ uschar * dstitem;
+ uschar * newlist = NULL;
+ uschar * newkeylist = NULL;
+ uschar * srcfield;
+
+ DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, srcitem);
+
+ /* extract field for comparisons */
+ iterate_item = srcitem;
+ if ( !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
+ TRUE, &resetok))
+ || !*srcfield)
+ {
+ expand_string_message = string_sprintf(
+ "field-extract in sort: \"%s\"", xtract);
+ goto EXPAND_FAILED;
+ }
+
+ /* Insertion sort */
+
+ /* copy output list until new-item < list-item */
+ while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
+ {
+ uschar * dstfield;
+ uschar * expr;
+ BOOL before;
+
+ /* field for comparison */
+ if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
+ goto sort_mismatch;
+
+ /* build and run condition string */
+ expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
+
+ DEBUG(D_expand) debug_printf("%s: cond = \"%s\"\n", name, expr);
+ if (!eval_condition(expr, &resetok, &before))
+ {
+ expand_string_message = string_sprintf("comparison in sort: %s",
+ expr);
+ goto EXPAND_FAILED;
+ }
+
+ if (before)
+ {
+ /* New-item sorts before this dst-item. Append new-item,
+ then dst-item, then remainder of dst list. */
+
+ newlist = string_append_listele(newlist, sep, srcitem);
+ newkeylist = string_append_listele(newkeylist, sep, srcfield);
+ srcitem = NULL;
+
+ newlist = string_append_listele(newlist, sep, dstitem);
+ newkeylist = string_append_listele(newkeylist, sep, dstfield);
+
+ while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
+ {
+ if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
+ goto sort_mismatch;
+ newlist = string_append_listele(newlist, sep, dstitem);
+ newkeylist = string_append_listele(newkeylist, sep, dstfield);
+ }
+
+ break;
+ }
+
+ newlist = string_append_listele(newlist, sep, dstitem);
+ newkeylist = string_append_listele(newkeylist, sep, dstfield);
+ }
+
+ /* If we ran out of dstlist without consuming srcitem, append it */
+ if (srcitem)
+ {
+ newlist = string_append_listele(newlist, sep, srcitem);
+ newkeylist = string_append_listele(newkeylist, sep, srcfield);
+ }
+
+ dstlist = newlist;
+ dstkeylist = newkeylist;
+
+ DEBUG(D_expand) debug_printf("%s: dstlist = \"%s\"\n", name, dstlist);
+ DEBUG(D_expand) debug_printf("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
+ }
+
+ if (dstlist)
+ yield = string_cat(yield, &size, &ptr, dstlist, Ustrlen(dstlist));
+
+ /* Restore preserved $item */
+ iterate_item = save_iterate_item;
+ continue;
+
+ sort_mismatch:
+ expand_string_message = US"Internal error in sort (list mismatch)";
+ goto EXPAND_FAILED;
+ }
+
+
+ /* If ${dlfunc } support is configured, handle calling dynamically-loaded