From 3bdea9dc42e4fdbb5842287133d5324a60f138ef Mon Sep 17 00:00:00 2001
From: Zephyr <12817816+ZephyrTFA@users.noreply.github.com>
Date: Sun, 26 Feb 2023 02:07:34 -0500
Subject: [PATCH] check for client disconnect during hud updates (#73588)

## About The Pull Request

Noticed a few runtimes about trying to read a null.prefs and tracked it
down to these lines.

When you go to create a hud for a mob, you add it to the client's
screen, however adding to a client's screen is an internal byond
operation and as such will allow a client disconnection to be processed.
## Why It's Good For The Game

Client DC catching is good, and some comments stating why it's needed
---
 code/modules/mob/login.dm | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/code/modules/mob/login.dm b/code/modules/mob/login.dm
index cda4e179fcc..55afd32a737 100644
--- a/code/modules/mob/login.dm
+++ b/code/modules/mob/login.dm
@@ -40,9 +40,14 @@
 	client.set_right_click_menu_mode(shift_to_open_context_menu)
 
 	if(!hud_used)
-		create_mob_hud()
+		create_mob_hud() // creating a hud will add it to the client's screen, which can process a disconnect
+		if(!client)
+			return FALSE
+
 	if(hud_used)
-		hud_used.show_hud(hud_used.hud_version)
+		hud_used.show_hud(hud_used.hud_version) // see above, this can process a disconnect
+		if(!client)
+			return FALSE
 		hud_used.update_ui_style(ui_style2icon(client.prefs?.read_preference(/datum/preference/choiced/ui_style)))
 
 	next_move = 1