From 515d5957602a87e5f255bba8d4d066a8aa91f42e Mon Sep 17 00:00:00 2001
From: Juhu <5894800-Juhu_@users.noreply.gitlab.com>
Date: Mon, 30 Jan 2023 03:03:19 +0100
Subject: [PATCH] q3df compat: remove IntrusiveList in entity field for
 trigger_push_velocity to avoid overflow crashes

---
 qcsrc/common/mapobjects/trigger/jumppads.qc | 61 ++++++++++++++++-----
 qcsrc/common/mapobjects/trigger/jumppads.qh |  6 +-
 2 files changed, 53 insertions(+), 14 deletions(-)

diff --git a/qcsrc/common/mapobjects/trigger/jumppads.qc b/qcsrc/common/mapobjects/trigger/jumppads.qc
index 17d1d57da..da2f8dc0b 100644
--- a/qcsrc/common/mapobjects/trigger/jumppads.qc
+++ b/qcsrc/common/mapobjects/trigger/jumppads.qc
@@ -226,13 +226,28 @@ vector trigger_push_velocity_calculatevelocity(entity this, vector org, entity t
 	return vs + '0 0 1' * vz;
 }
 
-void check_pushed(entity this)
+void check_pushed(entity this) // first jump pad to think thinks for every jump pad
 {
-	IL_EACH(this.pushed, WarpZoneLib_ExactTrigger_Touch(this, it),
+	IL_EACH(are_pushed, true,
 	{
-		IL_REMOVE(this.pushed, it);
+		bool empty = true;
+		for(int i = 0; i < MAX_PUSHED; ++i)
+		{
+			if(!it.has_pushed[i]) continue;
+			if(WarpZoneLib_ExactTrigger_Touch(it.has_pushed[i], it))
+			{
+				it.has_pushed[i] = NULL;
+				continue;
+			}
+			empty = false;
+		}
+		if(empty)
+		{
+			IL_REMOVE(are_pushed, it);
+		}
 	});
-	if(!IL_EMPTY(this.pushed))
+
+	if(!IL_EMPTY(are_pushed))
 	{
 		this.nextthink = time;
 	}
@@ -251,7 +266,35 @@ bool jumppad_push(entity this, entity targ, bool is_velocity_pad)
 		org.z += 1; // off by 1!
 	}
 
-	bool is_pushed = is_velocity_pad && IL_CONTAINS(this.pushed, targ);
+	bool is_pushed = false;
+	if(is_velocity_pad)
+	{
+		for(int i = 0; i < MAX_PUSHED; ++i)
+		{
+			if(this == targ.has_pushed[i])
+			{
+				is_pushed = true;
+				break;
+			}
+		}
+
+		if(!is_pushed && ((this.spawnflags & ADD_XY) || (this.spawnflags & ADD_Z))) // remember jump pads which boost on initial touch
+		{
+			bool limit_reached = true;
+			for(int i = 0; i < MAX_PUSHED; ++i)
+			{
+				if(targ.has_pushed[i]) continue;
+				limit_reached = false;
+				targ.has_pushed[i] = this; // may be briefly out of sync between client and server if client prediction is toggled
+			}
+			if(limit_reached)
+			{
+				return false; // too many overlapping jump pads
+			}
+			IL_PUSH(are_pushed, targ);
+			this.nextthink = time;
+		}
+	}
 
 	if(this.enemy)
 	{
@@ -299,12 +342,6 @@ bool jumppad_push(entity this, entity targ, bool is_velocity_pad)
 		}
 	}
 
-	if(is_velocity_pad && !is_pushed)
-	{
-		IL_PUSH(this.pushed, targ); // may be briefly out of sync between client and server if client prediction is toggled
-		this.nextthink = time;
-	}
-
 	if(!is_pushed) UNSET_ONGROUND(targ);
 
 #ifdef CSQC
@@ -823,7 +860,6 @@ spawnfunc(trigger_push_velocity)
 
 	trigger_push_velocity_link(this); // link it now
 
-	this.pushed = IL_NEW();
 	setthink(this, check_pushed);
 }
 
@@ -922,7 +958,6 @@ NET_HANDLE(ENT_CLIENT_TRIGGER_PUSH_VELOCITY, bool isnew)
 	this.solid = SOLID_TRIGGER;
 	settouch(this, trigger_push_velocity_touch);
 	this.move_time = time;
-	this.pushed = IL_NEW();
 	setthink(this, check_pushed);
 
 	return true;
diff --git a/qcsrc/common/mapobjects/trigger/jumppads.qh b/qcsrc/common/mapobjects/trigger/jumppads.qh
index 7be45ce93..51ec38d98 100644
--- a/qcsrc/common/mapobjects/trigger/jumppads.qh
+++ b/qcsrc/common/mapobjects/trigger/jumppads.qh
@@ -18,7 +18,11 @@ STATIC_INIT(g_jumppads) { g_jumppads = IL_NEW(); }
 .float pushltime;
 .bool istypefrag;
 .float height;
-.IntrusiveList pushed;
+
+const int MAX_PUSHED = 16; // maximum amount of jump pads which are allowed to push simultaneously
+.entity has_pushed[MAX_PUSHED];
+IntrusiveList are_pushed;
+STATIC_INIT(are_pushed) { are_pushed = IL_NEW(); }
 
 const int NUM_JUMPPADSUSED = 3;
 .float jumppadcount;
-- 
2.39.2