Fix potential wrong total time in trace info when the request is invalid

Author: git-hulk

request.go

@@ -1253,11 +1253,18 @@ func (r *Request) TraceInfo() TraceInfo {
 
 	// Calculate the total time accordingly,
 	// when connection is reused
+	var requestStartTime time.Time
 	if ct.gotConnInfo.Reused {
-		ti.TotalTime = ct.endTime.Sub(ct.getConn)
+		requestStartTime = ct.getConn
 	} else {
-		ti.TotalTime = ct.endTime.Sub(ct.dnsStart)
+		requestStartTime = ct.dnsStart
 	}
+	// DNS start and get conn time may be zero if the request is invalid.
+	// See issue #1016.
+	if requestStartTime.IsZero() {
+		requestStartTime = r.Time
+	}
+	ti.TotalTime = ct.endTime.Sub(requestStartTime)
 
 	// Only calculate on successful connections
 	if !ct.connectDone.IsZero() {

request_test.go

@@ -1830,6 +1830,18 @@ func TestTraceInfo(t *testing.T) {
 
 	})
 
+	t.Run("enable trace on invalid request, issue #1016", func(t *testing.T) {
+		resp, err := client.R().EnableTrace().Get("unknown://url.com")
+		assertNotNil(t, err)
+		tr := resp.Request.TraceInfo()
+		assertEqual(t, true, tr.DNSLookup == 0)
+		assertEqual(t, true, tr.ConnTime == 0)
+		assertEqual(t, true, tr.TLSHandshake == 0)
+		assertEqual(t, true, tr.ServerTime == 0)
+		assertEqual(t, true, tr.ResponseTime == 0)
+		assertEqual(t, true, tr.TotalTime > 0 && tr.TotalTime < time.Second)
+	})
+
 	t.Run("enable trace and debug on request", func(t *testing.T) {
 		c, logBuf := dcldb()
 		c.SetBaseURL(ts.URL)