From 1654a203eacf86e2a304f76eae79f0971810cc61 Mon Sep 17 00:00:00 2001
From: Demian <demian.getman@gmail.com>
Date: Thu, 16 Apr 2020 17:57:16 +0300
Subject: [PATCH] bot: check recipient for nil to avoid panics

---
 bot.go     | 20 ++++++++++++++++++--
 telebot.go |  1 +
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/bot.go b/bot.go
index da2b829..8d8fb89 100644
--- a/bot.go
+++ b/bot.go
@@ -513,6 +513,10 @@ func (b *Bot) Stop() {
 //
 // This function will panic upon unsupported payloads and options!
 func (b *Bot) Send(to Recipient, what interface{}, options ...interface{}) (*Message, error) {
+	if to == nil {
+		return nil, ErrBadRecipient
+	}
+
 	sendOpts := extractOptions(options)
 
 	switch object := what.(type) {
@@ -530,6 +534,10 @@ func (b *Bot) Send(to Recipient, what interface{}, options ...interface{}) (*Mes
 //
 // From all existing options, it only supports telebot.Silent.
 func (b *Bot) SendAlbum(to Recipient, a Album, options ...interface{}) ([]Message, error) {
+	if to == nil {
+		return nil, ErrBadRecipient
+	}
+
 	media := make([]string, len(a))
 	files := make(map[string]File)
 
@@ -652,6 +660,10 @@ func (b *Bot) Reply(to *Message, what interface{}, options ...interface{}) (*Mes
 //
 // This function will panic upon unsupported payloads and options!
 func (b *Bot) Forward(to Recipient, what *Message, options ...interface{}) (*Message, error) {
+	if to == nil {
+		return nil, ErrBadRecipient
+	}
+
 	params := map[string]string{
 		"chat_id":      to.Recipient(),
 		"from_chat_id": what.Chat.Recipient(),
@@ -943,9 +955,13 @@ func (b *Bot) Delete(message Editable) error {
 //
 // Currently, Telegram supports only a narrow range of possible
 // actions, these are aligned as constants of this package.
-func (b *Bot) Notify(recipient Recipient, action ChatAction) error {
+func (b *Bot) Notify(to Recipient, action ChatAction) error {
+	if to == nil {
+		return ErrBadRecipient
+	}
+
 	params := map[string]string{
-		"chat_id": recipient.Recipient(),
+		"chat_id": to.Recipient(),
 		"action":  string(action),
 	}
 
diff --git a/telebot.go b/telebot.go
index 8e91319..a66fdc0 100644
--- a/telebot.go
+++ b/telebot.go
@@ -31,6 +31,7 @@ package telebot
 import "github.com/pkg/errors"
 
 var (
+	ErrBadRecipient        = errors.New("telebot: recipient is nil")
 	ErrUnsupportedSendable = errors.New("telebot: unsupported sendable")
 )