feat!: don't override req.log if set during .first

lib/server.js

@@ -1294,7 +1294,13 @@ Server.prototype._setupRequest = function _setupRequest(req, res) {
 
     // Extend request
     req._dtraceId = dtrace.nextId();
-    req.log = res.log = self.log;
+    // if log is set on .first, don't override it
+    if (req.log === undefined) {
+        req.log = self.log;
+    }
+    if (res.log === undefined) {
+        res.log = req.log;
+    }
     req._date = new Date();
     req._timeStart = process.hrtime();
     req.serverName = self.name;

test/server.test.js

@@ -2953,3 +2953,44 @@ test('Server correctly handles multiple clientError listeners', function(t) {
         });
     }).end();
 });
+
+test('req and res should use server logger by default', function(t) {
+    SERVER.get('/ping', function echoId(req, res, next) {
+        t.ok(req.log);
+        t.strictEqual(req.log, SERVER.log);
+        req.log.info('foo');
+        t.equal(LOG_BUFFER.records[LOG_BUFFER.length - 1].msg, 'foo');
+        res.log.info('bar');
+        t.equal(LOG_BUFFER.records[LOG_BUFFER.length - 1].msg, 'bar');
+        res.send();
+        next();
+    });
+
+    CLIENT.get('/ping', function() {
+        t.end();
+    });
+});
+
+test('req and res should use own logger by if set during .first', function(t) {
+    const buffer = new StreamRecorder();
+    SERVER.first(function first(req, res) {
+        req.log = helper.getLog('server', buffer, 'info');
+    });
+
+    SERVER.get('/ping', function echoId(req, res, next) {
+        LOG_BUFFER.flushRecords();
+        t.ok(req.log);
+        t.notStrictEqual(req.log, SERVER.log);
+        req.log.info('foo');
+        t.equal(buffer.records[buffer.length - 1].msg, 'foo');
+        res.log.info('bar');
+        t.equal(buffer.records[buffer.length - 1].msg, 'bar');
+        t.equal(LOG_BUFFER.records.length, 0);
+        res.send();
+        next();
+    });
+
+    CLIENT.get('/ping', function() {
+        t.end();
+    });
+});