--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/hostip6.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,204 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+/***********************************************************************
+ * Only for IPv6-enabled builds
+ **********************************************************************/
+#ifdef CURLRES_IPV6
+
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef __VMS
+#include <in.h>
+#include <inet.h>
+#endif
+
+#ifdef HAVE_PROCESS_H
+#include <process.h>
+#endif
+
+#include "urldata.h"
+#include "sendf.h"
+#include "hostip.h"
+#include "hash.h"
+#include "share.h"
+#include "strerror.h"
+#include "url.h"
+#include "inet_pton.h"
+#include "connect.h"
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * Curl_ipv6works() returns TRUE if IPv6 seems to work.
+ */
+bool Curl_ipv6works(void)
+{
+  /* the nature of most system is that IPv6 status doesn't come and go
+     during a program's lifetime so we only probe the first time and then we
+     have the info kept for fast re-use */
+  static int ipv6_works = -1;
+  if(-1 == ipv6_works) {
+    /* probe to see if we have a working IPv6 stack */
+    curl_socket_t s = socket(PF_INET6, SOCK_DGRAM, 0);
+    if(s == CURL_SOCKET_BAD)
+      /* an IPv6 address was requested but we can't get/use one */
+      ipv6_works = 0;
+    else {
+      ipv6_works = 1;
+      Curl_closesocket(NULL, s);
+    }
+  }
+  return (ipv6_works>0)?TRUE:FALSE;
+}
+
+/*
+ * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
+ * been set and returns TRUE if they are OK.
+ */
+bool Curl_ipvalid(struct connectdata *conn)
+{
+  if(conn->ip_version == CURL_IPRESOLVE_V6)
+    return Curl_ipv6works();
+
+  return TRUE;
+}
+
+#if defined(CURLRES_SYNCH)
+
+#ifdef DEBUG_ADDRINFO
+static void dump_addrinfo(struct connectdata *conn, const Curl_addrinfo *ai)
+{
+  printf("dump_addrinfo:\n");
+  for(; ai; ai = ai->ai_next) {
+    char buf[INET6_ADDRSTRLEN];
+    printf("    fam %2d, CNAME %s, ",
+           ai->ai_family, ai->ai_canonname ? ai->ai_canonname : "<none>");
+    if(Curl_printable_address(ai, buf, sizeof(buf)))
+      printf("%s\n", buf);
+    else {
+      char buffer[STRERROR_LEN];
+      printf("failed; %s\n",
+             Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
+    }
+  }
+}
+#else
+#define dump_addrinfo(x,y) Curl_nop_stmt
+#endif
+
+/*
+ * Curl_getaddrinfo() when built IPv6-enabled (non-threading and
+ * non-ares version).
+ *
+ * Returns name information about the given hostname and port number. If
+ * successful, the 'addrinfo' is returned and the forth argument will point to
+ * memory we need to free after use. That memory *MUST* be freed with
+ * Curl_freeaddrinfo(), nothing else.
+ */
+Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
+                                const char *hostname,
+                                int port,
+                                int *waitp)
+{
+  struct addrinfo hints;
+  Curl_addrinfo *res;
+  int error;
+  char sbuf[12];
+  char *sbufptr = NULL;
+#ifndef USE_RESOLVE_ON_IPS
+  char addrbuf[128];
+#endif
+  int pf;
+#if !defined(CURL_DISABLE_VERBOSE_STRINGS)
+  struct Curl_easy *data = conn->data;
+#endif
+
+  *waitp = 0; /* synchronous response only */
+
+  /* Check if a limited name resolve has been requested */
+  switch(conn->ip_version) {
+  case CURL_IPRESOLVE_V4:
+    pf = PF_INET;
+    break;
+  case CURL_IPRESOLVE_V6:
+    pf = PF_INET6;
+    break;
+  default:
+    pf = PF_UNSPEC;
+    break;
+  }
+
+  if((pf != PF_INET) && !Curl_ipv6works())
+    /* The stack seems to be a non-IPv6 one */
+    pf = PF_INET;
+
+  memset(&hints, 0, sizeof(hints));
+  hints.ai_family = pf;
+  hints.ai_socktype = (conn->transport == TRNSPRT_TCP) ?
+    SOCK_STREAM : SOCK_DGRAM;
+
+#ifndef USE_RESOLVE_ON_IPS
+  /*
+   * The AI_NUMERICHOST must not be set to get synthesized IPv6 address from
+   * an IPv4 address on iOS and Mac OS X.
+   */
+  if((1 == Curl_inet_pton(AF_INET, hostname, addrbuf)) ||
+     (1 == Curl_inet_pton(AF_INET6, hostname, addrbuf))) {
+    /* the given address is numerical only, prevent a reverse lookup */
+    hints.ai_flags = AI_NUMERICHOST;
+  }
+#endif
+
+  if(port) {
+    msnprintf(sbuf, sizeof(sbuf), "%d", port);
+    sbufptr = sbuf;
+  }
+
+  error = Curl_getaddrinfo_ex(hostname, sbufptr, &hints, &res);
+  if(error) {
+    infof(data, "getaddrinfo(3) failed for %s:%d\n", hostname, port);
+    return NULL;
+  }
+
+  if(port) {
+    Curl_addrinfo_set_port(res, port);
+  }
+
+  dump_addrinfo(conn, res);
+
+  return res;
+}
+#endif /* CURLRES_SYNCH */
+
+#endif /* CURLRES_IPV6 */