From 813be25713b066a0382b8aa263b3aea7c5d27a32 Mon Sep 17 00:00:00 2001
From: "diamondburned (Forefront)" <datutbrus@gmail.com>
Date: Mon, 13 Apr 2020 18:23:38 -0700
Subject: [PATCH] Gateway: Fixed infinite InvalidSession loop

---
 gateway/gateway.go |  3 ++-
 gateway/op.go      | 18 ++++++------------
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/gateway/gateway.go b/gateway/gateway.go
index ebd992c..110115f 100644
--- a/gateway/gateway.go
+++ b/gateway/gateway.go
@@ -195,7 +195,7 @@ func (g *Gateway) Reconnect() {
 		// If the connection is rate limited (documented behavior):
 		// https://discordapp.com/developers/docs/topics/gateway#rate-limiting
 
-		if err := g.Open(); err != nil && err != ErrInvalidSession {
+		if err := g.Open(); err != nil {
 			g.ErrorLog(errors.Wrap(err, "Failed to open gateway"))
 			continue
 		}
@@ -282,6 +282,7 @@ func (g *Gateway) start() error {
 	// Expect either READY or RESUMED before continuing.
 	WSDebug("Waiting for either READY or RESUMED.")
 
+	// WaitForEvent should 
 	err := WaitForEvent(g, ch, func(op *OP) bool {
 		switch op.EventName {
 		case "READY":
diff --git a/gateway/op.go b/gateway/op.go
index 30fe00d..0410253 100644
--- a/gateway/op.go
+++ b/gateway/op.go
@@ -38,8 +38,6 @@ type OP struct {
 	EventName string `json:"t,omitempty"`
 }
 
-var ErrInvalidSession = errors.New("Invalid session")
-
 func DecodeEvent(driver json.Driver, ev wsutil.Event, v interface{}) (OPCode, error) {
 	op, err := DecodeOP(driver, ev)
 	if err != nil {
@@ -91,16 +89,16 @@ func WaitForEvent(g *Gateway, ch <-chan wsutil.Event, fn func(*OP) bool) error {
 			return err
 		}
 
-		// Are these events what we're looking for?
-		found := fn(o)
-
-		// Handle the *OP anyway.
+		// Handle the *OP first, in case it's an Invalid Session. This should
+		// also prevent a race condition with things that need Ready after
+		// Open().
 		if err := HandleOP(g, o); err != nil {
 			return err
 		}
 
-		// If we found the event, return.
-		if found {
+		// Are these events what we're looking for? If we've found the event,
+		// return.
+		if fn(o) {
 			return nil
 		}
 	}
@@ -122,10 +120,6 @@ func DecodeOP(driver json.Driver, ev wsutil.Event) (*OP, error) {
 		return nil, errors.Wrap(err, "OP error: "+string(ev.Data))
 	}
 
-	if op.Code == InvalidSessionOP {
-		return op, ErrInvalidSession
-	}
-
 	return op, nil
 }