tcp_pre_bind_handler returns a lib::error_code not an asio::error_code. These are sometimes the same but not always. Fix ensures that the error code types always match correctly no matter what they are. Update test suite to reflect adjusted behavior

test/endpoint/endpoint.cpp

@@ -147,8 +147,11 @@ BOOST_AUTO_TEST_CASE( listen_after_listen_failure ) {
     server1.listen(ep1, ec);
     BOOST_CHECK(!ec);
 
+    // This should return some sort of problem. Usually either "pass through" or
+    // a more specific address in use error. It is hard to capture the full range
+    // of 'correctly wrong' values.
     server2.listen(ep1, ec);
-    BOOST_REQUIRE_EQUAL(ec, make_error_code(pass_through));
+    BOOST_REQUIRE(ec);
 
     server2.listen(ep2, ec);
     BOOST_CHECK(!ec);

websocketpp/transport/asio/endpoint.hpp

@@ -425,30 +425,33 @@ public:
         lib::asio::error_code bec;
 
         m_acceptor->open(ep.protocol(),bec);
-        if (!bec) {
-            m_acceptor->set_option(lib::asio::socket_base::reuse_address(m_reuse_addr),bec);
-        }
-        if (!bec && m_tcp_pre_bind_handler) {
-            bec = m_tcp_pre_bind_handler(m_acceptor);
-        }
-        if (!bec) {
-            m_acceptor->bind(ep,bec);
-        }
-        if (!bec) {
-            m_acceptor->listen(m_listen_backlog,bec);
-        }
-        if (bec) {
-            if (m_acceptor->is_open()) {
-                m_acceptor->close();
+        if (bec) {ec = clean_up_listen_after_error(bec);return;}
+        
+        m_acceptor->set_option(lib::asio::socket_base::reuse_address(m_reuse_addr),bec);
+        if (bec) {ec = clean_up_listen_after_error(bec);return;}
+        
+        // if a TCP pre-bind handler is present, run it
+        if (m_tcp_pre_bind_handler) {
+            ec = m_tcp_pre_bind_handler(m_acceptor);
+            if (ec) {
+                ec = clean_up_listen_after_error(ec);
+                return;
             }
-            log_err(log::elevel::info,"asio listen",bec);
-            ec = socket_con_type::translate_ec(ec);
-        } else {
-            m_state = LISTENING;
-            ec = lib::error_code();
         }
+        
+        m_acceptor->bind(ep,bec);
+        if (bec) {ec = clean_up_listen_after_error(bec);return;}
+        
+        m_acceptor->listen(m_listen_backlog,bec);
+        if (bec) {ec = clean_up_listen_after_error(bec);return;}
+        
+        // Success
+        m_state = LISTENING;
+        ec = lib::error_code();
     }
 
+
+
     /// Set up endpoint for listening manually
     /**
      * Bind the internal acceptor using the settings specified by the endpoint e
@@ -1137,6 +1140,16 @@ private:
         m_elog->write(l,s.str());
     }
 
+    /// Helper for cleaning up in the listen method after an error
+    template <typename error_type>
+    lib::error_code clean_up_listen_after_error(error_type const & ec) {
+        if (m_acceptor->is_open()) {
+            m_acceptor->close();
+        }
+        log_err(log::elevel::info,"asio listen",ec);
+        return socket_con_type::translate_ec(ec);
+    }
+
     enum state {
         UNINITIALIZED = 0,
         READY = 1,