+#if defined(PHP_WIN32) || defined(HAVE_UIDNA_IDNTOASCII)
+typedef size_t (*parse_mb_func)(unsigned *wc, const char *ptr, const char *end);
+static ZEND_RESULT_CODE to_utf16(parse_mb_func fn, const char *u8, uint16_t **u16, size_t *len TSRMLS_DC)
+{
+ size_t offset = 0, u8_len = strlen(u8);
+
+ *u16 = ecalloc(4 * sizeof(uint16_t), u8_len + 1);
+ *len = 0;
+
+ while (offset < u8_len) {
+ unsigned wc;
+ uint16_t buf[2], *ptr = buf;
+ size_t consumed = fn(&wc, &u8[offset], &u8[u8_len]);
+
+ if (!consumed) {
+ efree(*u16);
+ php_error_docref(NULL TSRMLS_CC, E_WARNING, "Failed to parse UTF-8 at pos %zu of '%s'", offset, u8);
+ return FAILURE;
+ } else {
+ offset += consumed;
+ }
+
+ switch (wctoutf16(buf, wc)) {
+ case 2:
+ (*u16)[(*len)++] = *ptr++;
+ /* no break */
+ case 1:
+ (*u16)[(*len)++] = *ptr++;
+ break;
+ case 0:
+ default:
+ efree(*u16);
+ php_error_docref(NULL TSRMLS_CC, E_WARNING, "Failed to convert UTF-32 'U+%X' to UTF-16", wc);
+ return FAILURE;
+ }
+ }
+
+ return SUCCESS;
+}
+#endif
+
+#ifndef MAXHOSTNAMELEN
+# define MAXHOSTNAMELEN 256
+#endif
+
+#if PHP_HTTP_HAVE_IDN2
+static ZEND_RESULT_CODE parse_idn2(struct parse_state *state, size_t prev_len)
+{
+ char *idn = NULL;
+ int rv = -1;
+ TSRMLS_FETCH_FROM_CTX(state->ts);
+
+ if (state->flags & PHP_HTTP_URL_PARSE_MBUTF8) {
+ rv = idn2_lookup_u8((const unsigned char *) state->url.host, (unsigned char **) &idn, IDN2_NFC_INPUT);
+ }
+# ifdef PHP_HTTP_HAVE_WCHAR
+ else if (state->flags & PHP_HTTP_URL_PARSE_MBLOC) {
+ rv = idn2_lookup_ul(state->url.host, &idn, 0);
+ }
+# endif
+ if (rv != IDN2_OK) {
+ php_error_docref(NULL TSRMLS_CC, E_WARNING, "Failed to parse IDN; %s", idn2_strerror(rv));
+ return FAILURE;
+ } else {
+ size_t idnlen = strlen(idn);
+ memcpy(state->url.host, idn, idnlen + 1);
+ free(idn);
+ state->offset += idnlen - prev_len;
+ return SUCCESS;
+ }
+}
+#elif PHP_HTTP_HAVE_IDN
+static ZEND_RESULT_CODE parse_idn(struct parse_state *state, size_t prev_len)