plugin/forward: Use new msg.Id for upstream queries (#4841)

* restore 1.8.3 question revert logic; add tests (#4840)
Signed-off-by: Chris O'Haver <cohaver@infoblox.com>
Signed-off-by: Vector <815926354@qq.com>

* change origin message id
Signed-off-by: Vector <815926354@qq.com>
Signed-off-by: IIvyPy <815926354@qq.com>

* Revert "restore 1.8.3 question revert logic; add tests (#4840)"

This reverts commit 95e44d91d03452556f5a8af64371fcf5f0b642d0.
Signed-off-by: IIvyPy <815926354@qq.com>
Co-authored-by: Chris O'Haver <cohaver@infoblox.com>

plugin/forward/connect.go

@@ -97,6 +97,13 @@ func (p *Proxy) Connect(ctx context.Context, state request.Request, opts options
 	}
 
 	pc.c.SetWriteDeadline(time.Now().Add(maxTimeout))
+	// records the origin Id before upstream.
+	originId := state.Req.Id
+	state.Req.Id = dns.Id()
+	defer func(){
+		state.Req.Id = originId
+	}()
+
 	if err := pc.c.WriteMsg(state.Req); err != nil {
 		pc.c.Close() // not giving it back
 		if err == io.EOF && cached {
@@ -114,6 +121,10 @@ func (p *Proxy) Connect(ctx context.Context, state request.Request, opts options
 			if err == io.EOF && cached {
 				return nil, ErrCachedClosed
 			}
+			// recovery the origin Id after upstream.
+			if ret != nil{
+				ret.Id = originId
+			}
 			return ret, err
 		}
 		// drop out-of-order responses
@@ -121,6 +132,8 @@ func (p *Proxy) Connect(ctx context.Context, state request.Request, opts options
 			break
 		}
 	}
+	// recovery the origin Id after upstream.
+	ret.Id = originId
 
 	p.transport.Yield(pc)