dkforest

commit c04e9b629d8d9293bdb0ab8d565318d512d75dff
parent d365f5313c4de6dd56f76ccac5f8bd68775e7f7e
Author: n0tr1v <n0tr1v@protonmail.com>
Date:   Sat, 17 Jun 2023 11:56:06 -0700

Avoid double submission due to network lag

Diffstat:
M
pkg/web/handlers/chess.go
 | 
10
++++++----
M
pkg/web/handlers/interceptors/chess.go
 | 
5
+++++

2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/pkg/web/handlers/chess.go b/pkg/web/handlers/chess.go
@@ -429,6 +429,7 @@ button {
 	htmlTmpl := cssReset + interceptors.ChessCSS + `
 <form method="post">
 	<input type="hidden" name="csrf" value="{{ .CSRF }}" />
+	<input type="hidden" name="move_idx" value="{{ .MoveIdx }}" />
 	<table class="newBoard">
 		{{ range $row := .Rows }}
 			<tr>
@@ -460,10 +461,11 @@ button {
 </form>`
 
 	data := map[string]any{
-		"Rows": []int{0, 1, 2, 3, 4, 5, 6, 7},
-		"Cols": []int{0, 1, 2, 3, 4, 5, 6, 7},
-		"Key":  key,
-		"CSRF": csrf,
+		"Rows":    []int{0, 1, 2, 3, 4, 5, 6, 7},
+		"Cols":    []int{0, 1, 2, 3, 4, 5, 6, 7},
+		"Key":     key,
+		"CSRF":    csrf,
+		"MoveIdx": len(g.Game.Moves()),
 	}
 
 	fns := template.FuncMap{
diff --git a/pkg/web/handlers/interceptors/chess.go b/pkg/web/handlers/interceptors/chess.go
@@ -647,6 +647,11 @@ func (b *Chess) SendMove(gameKey string, userID database.UserID, g *ChessGame, c
 		return errors.New("not your turn")
 	}
 
+	moveIdx, _ := strconv.Atoi(c.Request().PostFormValue("move_idx"))
+	if moveIdx < len(g.Game.Moves())-1 {
+		return errors.New("double submission")
+	}
+
 	piecesCache := g.piecesCache
 
 	currentPlayer := player1