diff --git a/src/core/nginx.c b/src/core/nginx.c
index 9fcb0eb..f73e559 100644
--- a/src/core/nginx.c
+++ b/src/core/nginx.c
@@ -492,6 +492,7 @@ ngx_add_inherited_sockets(ngx_cycle_t *cycle)
             ngx_memzero(ls, sizeof(ngx_listening_t));
 
             ls->fd = (ngx_socket_t) s;
+            ls->inherited = 1;
         }
     }
 
diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c
index 3368253..88fefce 100644
--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -1070,7 +1070,8 @@ ngx_close_listening_sockets(ngx_cycle_t *cycle)
 
         if (ls[i].sockaddr->sa_family == AF_UNIX
             && ngx_process <= NGX_PROCESS_MASTER
-            && ngx_new_binary == 0)
+            && ngx_new_binary == 0
+            && (!ls[i].inherited || ngx_getppid() != ngx_parent))
         {
             u_char *name = ls[i].addr_text.data + sizeof("unix:") - 1;
 
diff --git a/src/core/ngx_cycle.c b/src/core/ngx_cycle.c
index 95f4bdf..764cf46 100644
--- a/src/core/ngx_cycle.c
+++ b/src/core/ngx_cycle.c
@@ -520,6 +520,7 @@ ngx_init_cycle(ngx_cycle_t *old_cycle)
                     == NGX_OK)
                 {
                     nls[n].fd = ls[i].fd;
+                    nls[n].inherited = ls[i].inherited;
                     nls[n].previous = &ls[i];
                     ls[i].remain = 1;
 
diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index 8531646..677bce4 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -928,6 +928,8 @@ ngx_int_t
 ngx_ssl_trusted_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *cert,
     ngx_int_t depth)
 {
+    SSL_CTX_set_verify(ssl->ctx, SSL_VERIFY_PEER, ngx_ssl_verify_callback);
+
     SSL_CTX_set_verify_depth(ssl->ctx, depth);
 
     if (cert->len == 0) {
diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index 5817a2c..f87e009 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -77,12 +77,11 @@ ngx_master_process_cycle(ngx_cycle_t *cycle)
     u_char            *p;
     size_t             size;
     ngx_int_t          i;
-    ngx_uint_t         n, sigio;
+    ngx_uint_t         sigio;
     sigset_t           set;
     struct itimerval   itv;
     ngx_uint_t         live;
     ngx_msec_t         delay;
-    ngx_listening_t   *ls;
     ngx_core_conf_t   *ccf;
 
     sigemptyset(&set);
@@ -204,16 +203,7 @@ ngx_master_process_cycle(ngx_cycle_t *cycle)
         if (ngx_quit) {
             ngx_signal_worker_processes(cycle,
                                         ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
-
-            ls = cycle->listening.elts;
-            for (n = 0; n < cycle->listening.nelts; n++) {
-                if (ngx_close_socket(ls[n].fd) == -1) {
-                    ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
-                                  ngx_close_socket_n " %V failed",
-                                  &ls[n].addr_text);
-                }
-            }
-            cycle->listening.nelts = 0;
+            ngx_close_listening_sockets(cycle);
 
             continue;
         }
diff --git a/src/os/unix/ngx_udp_sendmsg_chain.c b/src/os/unix/ngx_udp_sendmsg_chain.c
index 5399c79..3d1d6dd 100644
--- a/src/os/unix/ngx_udp_sendmsg_chain.c
+++ b/src/os/unix/ngx_udp_sendmsg_chain.c
@@ -189,6 +189,13 @@ ngx_udp_output_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *in, ngx_log_t *log)
         return cl;
     }
 
+    /* zero-sized datagram; pretend to have at least 1 iov */
+    if (n == 0) {
+        iov = &vec->iovs[n++];
+        iov->iov_base = NULL;
+        iov->iov_len = 0;
+    }
+
     vec->count = n;
     vec->size = total;
 
diff --git a/src/stream/ngx_stream_proxy_module.c b/src/stream/ngx_stream_proxy_module.c
index 6a47d73..e752859 100644
--- a/src/stream/ngx_stream_proxy_module.c
+++ b/src/stream/ngx_stream_proxy_module.c
@@ -839,7 +839,7 @@ ngx_stream_proxy_init_upstream(ngx_stream_session_t *s)
         u->upstream_buf.last = p;
     }
 
-    if (c->buffer && c->buffer->pos < c->buffer->last) {
+    if (c->buffer && c->buffer->pos <= c->buffer->last) {
         ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0,
                        "stream proxy add preread buffer: %uz",
                        c->buffer->last - c->buffer->pos);
@@ -853,6 +853,7 @@ ngx_stream_proxy_init_upstream(ngx_stream_session_t *s)
         *cl->buf = *c->buffer;
 
         cl->buf->tag = (ngx_buf_tag_t) &ngx_stream_proxy_module;
+        cl->buf->temporary = (cl->buf->pos == cl->buf->last) ? 0 : 1;
         cl->buf->flush = 1;
 
         cl->next = u->upstream_out;
diff --git a/src/stream/ngx_stream_write_filter_module.c b/src/stream/ngx_stream_write_filter_module.c
index 24326c6..156a61c 100644
--- a/src/stream/ngx_stream_write_filter_module.c
+++ b/src/stream/ngx_stream_write_filter_module.c
@@ -234,7 +234,8 @@ ngx_stream_write_filter(ngx_stream_session_t *s, ngx_chain_t *in,
 
     if (size == 0
         && !(c->buffered & NGX_LOWLEVEL_BUFFERED)
-        && !(last && c->need_last_buf))
+        && !(last && c->need_last_buf)
+        && !(c->type == SOCK_DGRAM && flush))
     {
         if (last || flush || sync) {
             for (cl = *out; cl; /* void */) {