1 files changed, 52 insertions, 125 deletions

diff --git a/lib/select.c b/lib/select.c
index abb124a..7d1f944 100644
--- a/lib/select.c
+++ b/lib/select.c
@@ -9,7 +9,7 @@
  *
  * 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.
+ * are also available at https://curl.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
@@ -149,15 +149,14 @@ int Curl_select(curl_socket_t maxfd,   /* highest socket number */
 {
   struct timeval pending_tv;
   struct timeval *ptimeout;
-  int r;
 
 #ifdef USE_WINSOCK
   /* WinSock select() can't handle zero events.  See the comment below. */
   if((!fds_read || fds_read->fd_count == 0) &&
      (!fds_write || fds_write->fd_count == 0) &&
      (!fds_err || fds_err->fd_count == 0)) {
-    r = Curl_wait_ms(timeout_ms);
-    return r;
+    /* no sockets, just wait */
+    return Curl_wait_ms(timeout_ms);
   }
 #endif
 
@@ -209,17 +208,16 @@ int Curl_select(curl_socket_t maxfd,   /* highest socket number */
     descriptor set must contain at least one handle to a socket.
 
     It is unclear why WinSock doesn't just handle this for us instead of
-    calling this an error.
+    calling this an error. Luckily, with WinSock, we can _also_ ask how
+    many bits are set on an fd_set. So, let's just check it beforehand.
   */
-  r = select((int)maxfd + 1,
-             fds_read && fds_read->fd_count ? fds_read : NULL,
-             fds_write && fds_write->fd_count ? fds_write : NULL,
-             fds_err && fds_err->fd_count ? fds_err : NULL, ptimeout);
+  return select((int)maxfd + 1,
+                fds_read && fds_read->fd_count ? fds_read : NULL,
+                fds_write && fds_write->fd_count ? fds_write : NULL,
+                fds_err && fds_err->fd_count ? fds_err : NULL, ptimeout);
 #else
-  r = select((int)maxfd + 1, fds_read, fds_write, fds_err, ptimeout);
+  return select((int)maxfd + 1, fds_read, fds_write, fds_err, ptimeout);
 #endif
-
-  return r;
 }
 
 /*
@@ -247,23 +245,14 @@ int Curl_socket_check(curl_socket_t readfd0, /* two sockets to read from */
                       curl_socket_t writefd, /* socket to write to */
                       timediff_t timeout_ms) /* milliseconds to wait */
 {
-#ifdef HAVE_POLL_FINE
   struct pollfd pfd[3];
   int num;
-#else
-  fd_set fds_read;
-  fd_set fds_write;
-  fd_set fds_err;
-  curl_socket_t maxfd;
-#endif
   int r;
-  int ret;
 
   if((readfd0 == CURL_SOCKET_BAD) && (readfd1 == CURL_SOCKET_BAD) &&
      (writefd == CURL_SOCKET_BAD)) {
     /* no sockets, just wait */
-    r = Curl_wait_ms(timeout_ms);
-    return r;
+    return Curl_wait_ms(timeout_ms);
   }
 
   /* Avoid initial timestamp, avoid Curl_now() call, when elapsed
@@ -271,8 +260,6 @@ int Curl_socket_check(curl_socket_t readfd0, /* two sockets to read from */
      when function is called with a zero timeout or a negative timeout
      value indicating a blocking call should be performed. */
 
-#ifdef HAVE_POLL_FINE
-
   num = 0;
   if(readfd0 != CURL_SOCKET_BAD) {
     pfd[num].fd = readfd0;
@@ -288,7 +275,7 @@ int Curl_socket_check(curl_socket_t readfd0, /* two sockets to read from */
   }
   if(writefd != CURL_SOCKET_BAD) {
     pfd[num].fd = writefd;
-    pfd[num].events = POLLWRNORM|POLLOUT;
+    pfd[num].events = POLLWRNORM|POLLOUT|POLLPRI;
     pfd[num].revents = 0;
     num++;
   }
@@ -297,101 +284,30 @@ int Curl_socket_check(curl_socket_t readfd0, /* two sockets to read from */
   if(r <= 0)
     return r;
 
-  ret = 0;
+  r = 0;
   num = 0;
   if(readfd0 != CURL_SOCKET_BAD) {
     if(pfd[num].revents & (POLLRDNORM|POLLIN|POLLERR|POLLHUP))
-      ret |= CURL_CSELECT_IN;
+      r |= CURL_CSELECT_IN;
     if(pfd[num].revents & (POLLRDBAND|POLLPRI|POLLNVAL))
-      ret |= CURL_CSELECT_ERR;
+      r |= CURL_CSELECT_ERR;
     num++;
   }
   if(readfd1 != CURL_SOCKET_BAD) {
     if(pfd[num].revents & (POLLRDNORM|POLLIN|POLLERR|POLLHUP))
-      ret |= CURL_CSELECT_IN2;
+      r |= CURL_CSELECT_IN2;
     if(pfd[num].revents & (POLLRDBAND|POLLPRI|POLLNVAL))
-      ret |= CURL_CSELECT_ERR;
+      r |= 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;
-  }
-
-  /* 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.
-
-     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).
-  */
-  r = Curl_select(maxfd, &fds_read, &fds_write, &fds_err, timeout_ms);
-
-  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;
+      r |= CURL_CSELECT_OUT;
+    if(pfd[num].revents & (POLLERR|POLLHUP|POLLPRI|POLLNVAL))
+      r |= CURL_CSELECT_ERR;
   }
 
-  return ret;
-
-#endif  /* HAVE_POLL_FINE */
-
+  return r;
 }
 
 /*
@@ -431,8 +347,7 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, timediff_t timeout_ms)
   }
   if(fds_none) {
     /* no sockets, just wait */
-    r = Curl_wait_ms(timeout_ms);
-    return r;
+    return Curl_wait_ms(timeout_ms);
   }
 
   /* Avoid initial timestamp, avoid Curl_now() call, when elapsed
@@ -454,11 +369,8 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, timediff_t timeout_ms)
   else
     pending_ms = 0;
   r = poll(ufds, nfds, pending_ms);
-
-  if(r < 0)
-    return -1;
-  if(r == 0)
-    return 0;
+  if(r <= 0)
+    return r;
 
   for(i = 0; i < nfds; i++) {
     if(ufds[i].fd == CURL_SOCKET_BAD)
@@ -466,7 +378,7 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, timediff_t timeout_ms)
     if(ufds[i].revents & POLLHUP)
       ufds[i].revents |= POLLIN;
     if(ufds[i].revents & POLLERR)
-      ufds[i].revents |= (POLLIN|POLLOUT);
+      ufds[i].revents |= POLLIN|POLLOUT;
   }
 
 #else  /* HAVE_POLL_FINE */
@@ -482,7 +394,7 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, timediff_t timeout_ms)
       continue;
     VERIFY_SOCK(ufds[i].fd);
     if(ufds[i].events & (POLLIN|POLLOUT|POLLPRI|
-                          POLLRDNORM|POLLWRNORM|POLLRDBAND)) {
+                         POLLRDNORM|POLLWRNORM|POLLRDBAND)) {
       if(ufds[i].fd > maxfd)
         maxfd = ufds[i].fd;
       if(ufds[i].events & (POLLRDNORM|POLLIN))
@@ -494,24 +406,39 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, timediff_t timeout_ms)
     }
   }
 
+  /*
+     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).
+  */
   r = Curl_select(maxfd, &fds_read, &fds_write, &fds_err, timeout_ms);
-
-  if(r < 0)
-    return -1;
-  if(r == 0)
-    return 0;
+  if(r <= 0)
+    return r;
 
   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(FD_ISSET(ufds[i].fd, &fds_read)) {
+      if(ufds[i].events & POLLRDNORM)
+        ufds[i].revents |= POLLRDNORM;
+      if(ufds[i].events & POLLIN)
+        ufds[i].revents |= POLLIN;
+    }
+    if(FD_ISSET(ufds[i].fd, &fds_write)) {
+      if(ufds[i].events & POLLWRNORM)
+        ufds[i].revents |= POLLWRNORM;
+      if(ufds[i].events & POLLOUT)
+        ufds[i].revents |= POLLOUT;
+    }
+    if(FD_ISSET(ufds[i].fd, &fds_err)) {
+      if(ufds[i].events & POLLRDBAND)
+        ufds[i].revents |= POLLRDBAND;
+      if(ufds[i].events & POLLPRI)
+        ufds[i].revents |= POLLPRI;
+    }
     if(ufds[i].revents != 0)
       r++;
   }