🐛 bug: fasthttp errors cause panic when Params is used (#3055)

Co-authored-by: Juan Calderon-Perez <835733+gaby@users.noreply.github.com>

ctx.go

@@ -1069,11 +1069,13 @@ func (c *DefaultCtx) Params(key string, defaultValue ...string) string {
 	if key == "*" || key == "+" {
 		key += "1"
 	}
-	for i := range c.route.Params {
+
+	route := c.Route()
+	for i := range route.Params {
 		if len(key) != len(c.route.Params[i]) {
 			continue
 		}
-		if c.route.Params[i] == key || (!c.app.config.CaseSensitive && utils.EqualFold(c.route.Params[i], key)) {
+		if route.Params[i] == key || (!c.app.config.CaseSensitive && utils.EqualFold(route.Params[i], key)) {
 			// in case values are not here
 			if len(c.values) <= i || len(c.values[i]) == 0 {
 				break

ctx_test.go

@@ -2372,6 +2372,25 @@ func Test_Ctx_Params(t *testing.T) {
 	require.Equal(t, StatusOK, resp.StatusCode, "Status code")
 }
 
+func Test_Ctx_Params_ErrorHandler_Panic_Issue_2832(t *testing.T) {
+	t.Parallel()
+
+	app := New(Config{
+		ErrorHandler: func(c Ctx, _ error) error {
+			return c.SendString(c.Params("user"))
+		},
+		BodyLimit: 1 * 1024,
+	})
+
+	app.Get("/test/:user", func(_ Ctx) error {
+		return NewError(StatusInternalServerError, "error")
+	})
+
+	largeBody := make([]byte, 2*1024)
+	_, err := app.Test(httptest.NewRequest(MethodGet, "/test/john", bytes.NewReader(largeBody)))
+	require.ErrorIs(t, err, fasthttp.ErrBodyTooLarge, "app.Test(req)")
+}
+
 func Test_Ctx_Params_Case_Sensitive(t *testing.T) {
 	t.Parallel()
 	app := New(Config{CaseSensitive: true})