--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/select.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,585 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2017, 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"
+
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
+#if !defined(HAVE_SELECT) && !defined(HAVE_POLL_FINE)
+#error "We can't compile without select() or poll() support."
+#endif
+
+#if defined(__BEOS__) && !defined(__HAIKU__)
+/* BeOS has FD_SET defined in socket.h */
+#include <socket.h>
+#endif
+
+#ifdef MSDOS
+#include <dos.h>  /* delay() */
+#endif
+
+#ifdef __VXWORKS__
+#include <strings.h>  /* bzero() in FD_SET */
+#endif
+
+#include <curl/curl.h>
+
+#include "urldata.h"
+#include "connect.h"
+#include "select.h"
+#include "warnless.h"
+
+/* Convenience local macros */
+#define ELAPSED_MS() (int)Curl_timediff(Curl_now(), initial_tv)
+
+int Curl_ack_eintr = 0;
+#define ERROR_NOT_EINTR(error) (Curl_ack_eintr || error != EINTR)
+
+/*
+ * Internal function used for waiting a specific amount of ms
+ * in Curl_socket_check() and Curl_poll() when no file descriptor
+ * is provided to wait on, just being used to delay execution.
+ * WinSock select() and poll() timeout mechanisms need a valid
+ * socket descriptor in a not null file descriptor set to work.
+ * Waiting indefinitely with this function is not allowed, a
+ * zero or negative timeout value will return immediately.
+ * Timeout resolution, accuracy, as well as maximum supported
+ * value is system dependent, neither factor is a citical issue
+ * for the intended use of this function in the library.
+ *
+ * Return values:
+ *   -1 = system call error, invalid timeout value, or interrupted
+ *    0 = specified timeout has elapsed
+ */
+int Curl_wait_ms(int timeout_ms)
+{
+#if !defined(MSDOS) && !defined(USE_WINSOCK)
+#ifndef HAVE_POLL_FINE
+  struct timeval pending_tv;
+#endif
+  struct curltime initial_tv;
+  int pending_ms;
+#endif
+  int r = 0;
+
+  if(!timeout_ms)
+    return 0;
+  if(timeout_ms < 0) {
+    SET_SOCKERRNO(EINVAL);
+    return -1;
+  }
+#if defined(MSDOS)
+  delay(timeout_ms);
+#elif defined(USE_WINSOCK)
+  Sleep(timeout_ms);
+#else
+  pending_ms = timeout_ms;
+  initial_tv = Curl_now();
+  do {
+    int error;
+#if defined(HAVE_POLL_FINE)
+    r = poll(NULL, 0, pending_ms);
+#else
+    pending_tv.tv_sec = pending_ms / 1000;
+    pending_tv.tv_usec = (pending_ms % 1000) * 1000;
+    r = select(0, NULL, NULL, NULL, &pending_tv);
+#endif /* HAVE_POLL_FINE */
+    if(r != -1)
+      break;
+    error = SOCKERRNO;
+    if(error && ERROR_NOT_EINTR(error))
+      break;
+    pending_ms = timeout_ms - ELAPSED_MS();
+    if(pending_ms <= 0) {
+      r = 0;  /* Simulate a "call timed out" case */
+      break;
+    }
+  } while(r == -1);
+#endif /* USE_WINSOCK */
+  if(r)
+    r = -1;
+  return r;
+}
+
+/*
+ * Wait for read or write events on a set of file descriptors. It uses poll()
+ * when a fine poll() is available, in order to avoid limits with FD_SETSIZE,
+ * otherwise select() is used.  An error is returned if select() is being used
+ * and a file descriptor is too large for FD_SETSIZE.
+ *
+ * A negative timeout value makes this function wait indefinitely,
+ * unless no valid file descriptor is given, when this happens the
+ * negative timeout is ignored and the function times out immediately.
+ *
+ * Return values:
+ *   -1 = system call error or fd >= FD_SETSIZE
+ *    0 = timeout
+ *    [bitmask] = action as described below
+ *
+ * CURL_CSELECT_IN - first socket is readable
+ * CURL_CSELECT_IN2 - second socket is readable
+ * CURL_CSELECT_OUT - write socket is writable
+ * CURL_CSELECT_ERR - an error condition occurred
+ */
+int Curl_socket_check(curl_socket_t readfd0, /* two sockets to read from */
+                      curl_socket_t readfd1,
+                      curl_socket_t writefd, /* socket to write to */
+                      time_t timeout_ms)     /* milliseconds to wait */
+{
+#ifdef HAVE_POLL_FINE
+  struct pollfd pfd[3];
+  int num;
+#else
+  struct timeval pending_tv;
+  struct timeval *ptimeout;
+  fd_set fds_read;
+  fd_set fds_write;
+  fd_set fds_err;
+  curl_socket_t maxfd;
+#endif
+  struct curltime initial_tv = {0, 0};
+  int pending_ms = 0;
+  int r;
+  int ret;
+
+#if SIZEOF_TIME_T != SIZEOF_INT
+  /* wrap-around precaution */
+  if(timeout_ms >= INT_MAX)
+    timeout_ms = INT_MAX;
+#endif
+
+  if((readfd0 == CURL_SOCKET_BAD) && (readfd1 == CURL_SOCKET_BAD) &&
+     (writefd == CURL_SOCKET_BAD)) {
+    /* no sockets, just wait */
+    r = Curl_wait_ms((int)timeout_ms);
+    return r;
+  }
+
+  /* Avoid initial timestamp, avoid Curl_now() call, when elapsed
+     time in this function does not need to be measured. This happens
+     when function is called with a zero timeout or a negative timeout
+     value indicating a blocking call should be performed. */
+
+  if(timeout_ms > 0) {
+    pending_ms = (int)timeout_ms;
+    initial_tv = Curl_now();
+  }
+
+#ifdef HAVE_POLL_FINE
+
+  num = 0;
+  if(readfd0 != CURL_SOCKET_BAD) {
+    pfd[num].fd = readfd0;
+    pfd[num].events = POLLRDNORM|POLLIN|POLLRDBAND|POLLPRI;
+    pfd[num].revents = 0;
+    num++;
+  }
+  if(readfd1 != CURL_SOCKET_BAD) {
+    pfd[num].fd = readfd1;
+    pfd[num].events = POLLRDNORM|POLLIN|POLLRDBAND|POLLPRI;
+    pfd[num].revents = 0;
+    num++;
+  }
+  if(writefd != CURL_SOCKET_BAD) {
+    pfd[num].fd = writefd;
+    pfd[num].events = POLLWRNORM|POLLOUT;
+    pfd[num].revents = 0;
+    num++;
+  }
+
+  do {
+    int error;
+    if(timeout_ms < 0)
+      pending_ms = -1;
+    else if(!timeout_ms)
+      pending_ms = 0;
+    r = poll(pfd, num, pending_ms);
+    if(r != -1)
+      break;
+    error = SOCKERRNO;
+    if(error && ERROR_NOT_EINTR(error))
+      break;
+    if(timeout_ms > 0) {
+      pending_ms = (int)(timeout_ms - ELAPSED_MS());
+      if(pending_ms <= 0) {
+        r = 0;  /* Simulate a "call timed out" case */
+        break;
+      }
+    }
+  } while(r == -1);
+
+  if(r < 0)
+    return -1;
+  if(r == 0)
+    return 0;
+
+  ret = 0;
+  num = 0;
+  if(readfd0 != CURL_SOCKET_BAD) {
+    if(pfd[num].revents & (POLLRDNORM|POLLIN|POLLERR|POLLHUP))
+      ret |= CURL_CSELECT_IN;
+    if(pfd[num].revents & (POLLRDBAND|POLLPRI|POLLNVAL))
+      ret |= CURL_CSELECT_ERR;
+    num++;
+  }
+  if(readfd1 != CURL_SOCKET_BAD) {
+    if(pfd[num].revents & (POLLRDNORM|POLLIN|POLLERR|POLLHUP))
+      ret |= CURL_CSELECT_IN2;
+    if(pfd[num].revents & (POLLRDBAND|POLLPRI|POLLNVAL))
+      ret |= CURL_CSELECT_ERR;
+    num++;
+  }
+  if(writefd != CURL_SOCKET_BAD) {
+    if(pfd[num].revents & (POLLWRNORM|POLLOUT))
+      ret |= CURL_CSELECT_OUT;
+    if(pfd[num].revents & (POLLERR|POLLHUP|POLLNVAL))
+      ret |= CURL_CSELECT_ERR;
+  }
+
+  return ret;
+
+#else  /* HAVE_POLL_FINE */
+
+  FD_ZERO(&fds_err);
+  maxfd = (curl_socket_t)-1;
+
+  FD_ZERO(&fds_read);
+  if(readfd0 != CURL_SOCKET_BAD) {
+    VERIFY_SOCK(readfd0);
+    FD_SET(readfd0, &fds_read);
+    FD_SET(readfd0, &fds_err);
+    maxfd = readfd0;
+  }
+  if(readfd1 != CURL_SOCKET_BAD) {
+    VERIFY_SOCK(readfd1);
+    FD_SET(readfd1, &fds_read);
+    FD_SET(readfd1, &fds_err);
+    if(readfd1 > maxfd)
+      maxfd = readfd1;
+  }
+
+  FD_ZERO(&fds_write);
+  if(writefd != CURL_SOCKET_BAD) {
+    VERIFY_SOCK(writefd);
+    FD_SET(writefd, &fds_write);
+    FD_SET(writefd, &fds_err);
+    if(writefd > maxfd)
+      maxfd = writefd;
+  }
+
+  ptimeout = (timeout_ms < 0) ? NULL : &pending_tv;
+
+  do {
+    int error;
+    if(timeout_ms > 0) {
+      pending_tv.tv_sec = pending_ms / 1000;
+      pending_tv.tv_usec = (pending_ms % 1000) * 1000;
+    }
+    else if(!timeout_ms) {
+      pending_tv.tv_sec = 0;
+      pending_tv.tv_usec = 0;
+    }
+
+    /* WinSock select() must not be called with an fd_set that contains zero
+       fd flags, or it will return WSAEINVAL.  But, it also can't be called
+       with no fd_sets at all!  From the documentation:
+
+         Any two of the parameters, readfds, writefds, or exceptfds, can be
+         given as null. At least one must be non-null, and any non-null
+         descriptor set must contain at least one handle to a socket.
+
+       We know that we have at least one bit set in at least two fd_sets in
+       this case, but we may have no bits set in either fds_read or fd_write,
+       so check for that and handle it.  Luckily, with WinSock, we can _also_
+       ask how many bits are set on an fd_set.
+
+       It is unclear why WinSock doesn't just handle this for us instead of
+       calling this an error.
+
+       Note also that WinSock ignores the first argument, so we don't worry
+       about the fact that maxfd is computed incorrectly with WinSock (since
+       curl_socket_t is unsigned in such cases and thus -1 is the largest
+       value).
+    */
+#ifdef USE_WINSOCK
+    r = select((int)maxfd + 1,
+               fds_read.fd_count ? &fds_read : NULL,
+               fds_write.fd_count ? &fds_write : NULL,
+               &fds_err, ptimeout);
+#else
+    r = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, ptimeout);
+#endif
+
+    if(r != -1)
+      break;
+    error = SOCKERRNO;
+    if(error && ERROR_NOT_EINTR(error))
+      break;
+    if(timeout_ms > 0) {
+      pending_ms = (int)(timeout_ms - ELAPSED_MS());
+      if(pending_ms <= 0) {
+        r = 0;  /* Simulate a "call timed out" case */
+        break;
+      }
+    }
+  } while(r == -1);
+
+  if(r < 0)
+    return -1;
+  if(r == 0)
+    return 0;
+
+  ret = 0;
+  if(readfd0 != CURL_SOCKET_BAD) {
+    if(FD_ISSET(readfd0, &fds_read))
+      ret |= CURL_CSELECT_IN;
+    if(FD_ISSET(readfd0, &fds_err))
+      ret |= CURL_CSELECT_ERR;
+  }
+  if(readfd1 != CURL_SOCKET_BAD) {
+    if(FD_ISSET(readfd1, &fds_read))
+      ret |= CURL_CSELECT_IN2;
+    if(FD_ISSET(readfd1, &fds_err))
+      ret |= CURL_CSELECT_ERR;
+  }
+  if(writefd != CURL_SOCKET_BAD) {
+    if(FD_ISSET(writefd, &fds_write))
+      ret |= CURL_CSELECT_OUT;
+    if(FD_ISSET(writefd, &fds_err))
+      ret |= CURL_CSELECT_ERR;
+  }
+
+  return ret;
+
+#endif  /* HAVE_POLL_FINE */
+
+}
+
+/*
+ * This is a wrapper around poll().  If poll() does not exist, then
+ * select() is used instead.  An error is returned if select() is
+ * being used and a file descriptor is too large for FD_SETSIZE.
+ * A negative timeout value makes this function wait indefinitely,
+ * unless no valid file descriptor is given, when this happens the
+ * negative timeout is ignored and the function times out immediately.
+ *
+ * Return values:
+ *   -1 = system call error or fd >= FD_SETSIZE
+ *    0 = timeout
+ *    N = number of structures with non zero revent fields
+ */
+int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms)
+{
+#ifndef HAVE_POLL_FINE
+  struct timeval pending_tv;
+  struct timeval *ptimeout;
+  fd_set fds_read;
+  fd_set fds_write;
+  fd_set fds_err;
+  curl_socket_t maxfd;
+#endif
+  struct curltime initial_tv = {0, 0};
+  bool fds_none = TRUE;
+  unsigned int i;
+  int pending_ms = 0;
+  int r;
+
+  if(ufds) {
+    for(i = 0; i < nfds; i++) {
+      if(ufds[i].fd != CURL_SOCKET_BAD) {
+        fds_none = FALSE;
+        break;
+      }
+    }
+  }
+  if(fds_none) {
+    r = Curl_wait_ms(timeout_ms);
+    return r;
+  }
+
+  /* Avoid initial timestamp, avoid Curl_now() call, when elapsed
+     time in this function does not need to be measured. This happens
+     when function is called with a zero timeout or a negative timeout
+     value indicating a blocking call should be performed. */
+
+  if(timeout_ms > 0) {
+    pending_ms = timeout_ms;
+    initial_tv = Curl_now();
+  }
+
+#ifdef HAVE_POLL_FINE
+
+  do {
+    int error;
+    if(timeout_ms < 0)
+      pending_ms = -1;
+    else if(!timeout_ms)
+      pending_ms = 0;
+    r = poll(ufds, nfds, pending_ms);
+    if(r != -1)
+      break;
+    error = SOCKERRNO;
+    if(error && ERROR_NOT_EINTR(error))
+      break;
+    if(timeout_ms > 0) {
+      pending_ms = (int)(timeout_ms - ELAPSED_MS());
+      if(pending_ms <= 0) {
+        r = 0;  /* Simulate a "call timed out" case */
+        break;
+      }
+    }
+  } while(r == -1);
+
+  if(r < 0)
+    return -1;
+  if(r == 0)
+    return 0;
+
+  for(i = 0; i < nfds; i++) {
+    if(ufds[i].fd == CURL_SOCKET_BAD)
+      continue;
+    if(ufds[i].revents & POLLHUP)
+      ufds[i].revents |= POLLIN;
+    if(ufds[i].revents & POLLERR)
+      ufds[i].revents |= (POLLIN|POLLOUT);
+  }
+
+#else  /* HAVE_POLL_FINE */
+
+  FD_ZERO(&fds_read);
+  FD_ZERO(&fds_write);
+  FD_ZERO(&fds_err);
+  maxfd = (curl_socket_t)-1;
+
+  for(i = 0; i < nfds; i++) {
+    ufds[i].revents = 0;
+    if(ufds[i].fd == CURL_SOCKET_BAD)
+      continue;
+    VERIFY_SOCK(ufds[i].fd);
+    if(ufds[i].events & (POLLIN|POLLOUT|POLLPRI|
+                          POLLRDNORM|POLLWRNORM|POLLRDBAND)) {
+      if(ufds[i].fd > maxfd)
+        maxfd = ufds[i].fd;
+      if(ufds[i].events & (POLLRDNORM|POLLIN))
+        FD_SET(ufds[i].fd, &fds_read);
+      if(ufds[i].events & (POLLWRNORM|POLLOUT))
+        FD_SET(ufds[i].fd, &fds_write);
+      if(ufds[i].events & (POLLRDBAND|POLLPRI))
+        FD_SET(ufds[i].fd, &fds_err);
+    }
+  }
+
+#ifdef USE_WINSOCK
+  /* WinSock select() can't handle zero events.  See the comment about this in
+     Curl_check_socket(). */
+  if(fds_read.fd_count == 0 && fds_write.fd_count == 0
+     && fds_err.fd_count == 0) {
+    r = Curl_wait_ms(timeout_ms);
+    return r;
+  }
+#endif
+
+  ptimeout = (timeout_ms < 0) ? NULL : &pending_tv;
+
+  do {
+    int error;
+    if(timeout_ms > 0) {
+      pending_tv.tv_sec = pending_ms / 1000;
+      pending_tv.tv_usec = (pending_ms % 1000) * 1000;
+    }
+    else if(!timeout_ms) {
+      pending_tv.tv_sec = 0;
+      pending_tv.tv_usec = 0;
+    }
+
+#ifdef USE_WINSOCK
+    r = select((int)maxfd + 1,
+               /* WinSock select() can't handle fd_sets with zero bits set, so
+                  don't give it such arguments.  See the comment about this in
+                  Curl_check_socket().
+               */
+               fds_read.fd_count ? &fds_read : NULL,
+               fds_write.fd_count ? &fds_write : NULL,
+               fds_err.fd_count ? &fds_err : NULL, ptimeout);
+#else
+    r = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, ptimeout);
+#endif
+    if(r != -1)
+      break;
+    error = SOCKERRNO;
+    if(error && ERROR_NOT_EINTR(error))
+      break;
+    if(timeout_ms > 0) {
+      pending_ms = timeout_ms - ELAPSED_MS();
+      if(pending_ms <= 0) {
+        r = 0;  /* Simulate a "call timed out" case */
+        break;
+      }
+    }
+  } while(r == -1);
+
+  if(r < 0)
+    return -1;
+  if(r == 0)
+    return 0;
+
+  r = 0;
+  for(i = 0; i < nfds; i++) {
+    ufds[i].revents = 0;
+    if(ufds[i].fd == CURL_SOCKET_BAD)
+      continue;
+    if(FD_ISSET(ufds[i].fd, &fds_read))
+      ufds[i].revents |= POLLIN;
+    if(FD_ISSET(ufds[i].fd, &fds_write))
+      ufds[i].revents |= POLLOUT;
+    if(FD_ISSET(ufds[i].fd, &fds_err))
+      ufds[i].revents |= POLLPRI;
+    if(ufds[i].revents != 0)
+      r++;
+  }
+
+#endif  /* HAVE_POLL_FINE */
+
+  return r;
+}
+
+#ifdef TPF
+/*
+ * This is a replacement for select() on the TPF platform.
+ * It is used whenever libcurl calls select().
+ * The call below to tpf_process_signals() is required because
+ * TPF's select calls are not signal interruptible.
+ *
+ * Return values are the same as select's.
+ */
+int tpf_select_libcurl(int maxfds, fd_set *reads, fd_set *writes,
+                       fd_set *excepts, struct timeval *tv)
+{
+   int rc;
+
+   rc = tpf_select_bsd(maxfds, reads, writes, excepts, tv);
+   tpf_process_signals();
+   return rc;
+}
+#endif /* TPF */