Brought grpc_server_add_secure_http2_port in line with grpc_server_http2_port

include/grpc/grpc.h

@@ -428,7 +428,8 @@ grpc_server *grpc_server_create(grpc_completion_queue *cq,
    REQUIRES: server not started */
 int grpc_server_add_http2_port(grpc_server *server, const char *addr);
 
-/* Add a secure port to server; returns 1 on success, 0 on failure
+/* Add a secure port to server.
+   Returns bound port number on success, 0 on failure.
    REQUIRES: server not started */
 int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr);
 

src/core/security/server_secure_chttp2.c

@@ -93,6 +93,8 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr) {
   grpc_tcp_server *tcp = NULL;
   size_t i;
   int count = 0;
+  int port_num = -1;
+  int port_temp;
 
   resolved = grpc_blocking_resolve_address(addr, "https");
   if (!resolved) {
@@ -105,9 +107,15 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr) {
   }
 
   for (i = 0; i < resolved->naddrs; i++) {
-    if (grpc_tcp_server_add_port(tcp,
-                                 (struct sockaddr *)&resolved->addrs[i].addr,
-                                 resolved->addrs[i].len)) {
+    port_temp = grpc_tcp_server_add_port(
+        tcp, (struct sockaddr *)&resolved->addrs[i].addr,
+        resolved->addrs[i].len);
+    if (port_temp >= 0) {
+      if (port_num == -1) {
+        port_num = port_temp;
+      } else {
+        GPR_ASSERT(port_num == port_temp);
+      }
       count++;
     }
   }
@@ -125,7 +133,7 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr) {
   /* Register with the server only upon success */
   grpc_server_add_listener(server, tcp, start, destroy);
 
-  return 1;
+  return port_num;
 
 /* Error path: cleanup and return */
 error: