select: align poll emulation to return all relevant events

The poll emulation via select already consumes POLLRDNORM,
POLLWRNORM and POLLRDBAND as input events. Therefore it
should also return them as output events if signaled.

Also fix indentation in input event handling block.

Assisted-by: Jay Satiro
Reviewed-by: Daniel Stenberg

Replaces #5852
Closes #5883

lib/select.c

@@ -378,7 +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 */
@@ -394,7 +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))
@@ -421,12 +421,24 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, timediff_t timeout_ms)
     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++;
   }