/* Check for valid interpolation. */
if (i < ninterps) {
value = interps[i].value;
- valuelen = strlen(value);
+ if (!value) {
+ src += namelen;
+ continue;
+ }
+ valuelen = strlen(value);
if (newlen + valuelen + 1 < reslen) {
/* Substitute. */
strncpy(dest, value, valuelen);