+ if (i == 0)
+ {
+ int len;
+ int x = 0;
+ uschar *p = sub[0];
+
+ while (isspace(*p)) p++;
+ sub[0] = p;
+
+ len = Ustrlen(p);
+ while (len > 0 && isspace(p[len-1])) len--;
+ p[len] = 0;
+
+ if (*p == 0 && !skipping)
+ {
+ expand_string_message = US"first argument of \"extract\" must "
+ "not be empty";
+ goto EXPAND_FAILED;
+ }
+
+ if (*p == '-')
+ {
+ field_number = -1;
+ p++;
+ }
+ while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
+ if (*p == 0)
+ {
+ field_number *= x;
+ j = 3; /* Need 3 args */
+ field_number_set = TRUE;
+ }
+ }
+ }
+ else goto EXPAND_FAILED_CURLY;
+ }
+
+ /* Extract either the numbered or the keyed substring into $value. If
+ skipping, just pretend the extraction failed. */
+
+ lookup_value = skipping? NULL : field_number_set?
+ expand_gettokened(field_number, sub[1], sub[2]) :
+ expand_getkeyed(sub[0], sub[1]);
+
+ /* If no string follows, $value gets substituted; otherwise there can
+ be yes/no strings, as for lookup or if. */
+
+ switch(process_yesno(
+ skipping, /* were previously skipping */
+ lookup_value != NULL, /* success/failure indicator */
+ save_lookup_value, /* value to reset for string2 */
+ &s, /* input pointer */
+ &yield, /* output pointer */
+ &size, /* output size */
+ &ptr, /* output current point */
+ US"extract")) /* condition type */
+ {
+ case 1: goto EXPAND_FAILED; /* when all is well, the */
+ case 2: goto EXPAND_FAILED_CURLY; /* returned value is 0 */
+ }
+
+ /* All done - restore numerical variables. */
+
+ restore_expand_strings(save_expand_nmax, save_expand_nstring,
+ save_expand_nlength);
+
+ continue;
+ }
+
+
+ /* Handle list operations */
+
+ case EITEM_FILTER:
+ case EITEM_MAP:
+ case EITEM_REDUCE:
+ {
+ int sep = 0;
+ int save_ptr = ptr;
+ uschar outsep[2] = { '\0', '\0' };
+ uschar *list, *expr, *temp;
+ uschar *save_iterate_item = iterate_item;
+ uschar *save_lookup_value = lookup_value;
+
+ while (isspace(*s)) s++;
+ if (*s++ != '{') goto EXPAND_FAILED_CURLY;
+
+ list = expand_string_internal(s, TRUE, &s, skipping, TRUE);
+ if (list == NULL) goto EXPAND_FAILED;
+ if (*s++ != '}') goto EXPAND_FAILED_CURLY;
+
+ if (item_type == EITEM_REDUCE)
+ {
+ while (isspace(*s)) s++;
+ if (*s++ != '{') goto EXPAND_FAILED_CURLY;
+ temp = expand_string_internal(s, TRUE, &s, skipping, TRUE);
+ if (temp == NULL) goto EXPAND_FAILED;
+ lookup_value = temp;
+ if (*s++ != '}') goto EXPAND_FAILED_CURLY;
+ }
+
+ while (isspace(*s)) s++;
+ if (*s++ != '{') goto EXPAND_FAILED_CURLY;
+
+ expr = s;
+
+ /* For EITEM_FILTER, call eval_condition once, with result discarded (as
+ if scanning a "false" part). This allows us to find the end of the
+ condition, because if the list is empty, we won't actually evaluate the
+ condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
+ the normal internal expansion function. */
+
+ if (item_type == EITEM_FILTER)
+ {
+ temp = eval_condition(expr, NULL);
+ if (temp != NULL) s = temp;
+ }
+ else
+ {
+ temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE);
+ }
+
+ if (temp == NULL)
+ {
+ expand_string_message = string_sprintf("%s inside \"%s\" item",
+ expand_string_message, name);
+ goto EXPAND_FAILED;
+ }
+
+ while (isspace(*s)) s++;
+ if (*s++ != '}')
+ {
+ expand_string_message = string_sprintf("missing } at end of condition "
+ "or expression inside \"%s\"", name);
+ goto EXPAND_FAILED;
+ }
+
+ while (isspace(*s)) s++;
+ if (*s++ != '}')
+ {
+ expand_string_message = string_sprintf("missing } at end of \"%s\"",
+ name);
+ goto EXPAND_FAILED;
+ }
+
+ /* If we are skipping, we can now just move on to the next item. When
+ processing for real, we perform the iteration. */
+
+ if (skipping) continue;
+ while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
+ {
+ *outsep = (uschar)sep; /* Separator as a string */
+
+ DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
+
+ if (item_type == EITEM_FILTER)
+ {
+ BOOL condresult;
+ if (eval_condition(expr, &condresult) == NULL)
+ {
+ iterate_item = save_iterate_item;
+ lookup_value = save_lookup_value;
+ expand_string_message = string_sprintf("%s inside \"%s\" condition",
+ expand_string_message, name);
+ goto EXPAND_FAILED;
+ }
+ DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
+ condresult? "true":"false");
+ if (condresult)
+ temp = iterate_item; /* TRUE => include this item */
+ else
+ continue; /* FALSE => skip this item */
+ }
+
+ /* EITEM_MAP and EITEM_REDUCE */
+
+ else
+ {
+ temp = expand_string_internal(expr, TRUE, NULL, skipping, TRUE);
+ if (temp == NULL)