- /* Here, the string should be converted to utf8, either because of an
- * input flag (two_byte_count = 0), or because a character that
- * requires 2 bytes was found (two_byte_count = 1). t points either to
- * the beginning of the string (if we didn't examine anything), or to
- * the first variant. In either case, everything from s to t - 1 will
- * occupy only 1 byte each on output.
+ /* Note that the incoming SV may not have a trailing '\0', as certain
+ * code in pp_formline can send us partially built SVs.
+ *
+ * Here, the string should be converted to utf8, either because of an
+ * input flag (which causes two_byte_count to be set to 0), or because
+ * a character that requires 2 bytes was found (two_byte_count = 1). t
+ * points either to the beginning of the string (if we didn't examine
+ * anything), or to the first variant. In either case, everything from
+ * s to t - 1 will occupy only 1 byte each on output.