From 3e3fe6be6df324ed1aa3562d814afe2e19c857d6 Mon Sep 17 00:00:00 2001
From: Dirk D <bluthund23@gmail.com>
Date: Thu, 18 Nov 2021 01:34:04 +0100
Subject: [PATCH 1/2] Attribute infighting kills to a player in netgames

---
 src/doom/p_inter.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/doom/p_inter.c b/src/doom/p_inter.c
index 15e0729827..801175db8b 100644
--- a/src/doom/p_inter.c
+++ b/src/doom/p_inter.c
@@ -742,11 +742,29 @@ P_KillMobj
 	if (target->player)
 	    source->player->frags[target->player-players]++;
     }
-    else if (!netgame && (target->flags & MF_COUNTKILL) )
+    else if (target->flags & MF_COUNTKILL)
     {
 	// count all monster deaths,
 	// even those caused by other monsters
-	players[0].killcount++;
+        if (!netgame)
+        {
+	    players[0].killcount++;
+        }
+        else // netgame
+        {
+            if (!deathmatch)
+            {
+                // add kill to first player who is still ingame
+                for (unsigned int plridx = 0; plridx < MAXPLAYERS; plridx++)
+                {
+                    if (playeringame[plridx])
+                    {
+                        players[plridx].killcount++;
+                        break;
+                    }
+                }
+            }
+        }
     }
     
     if (target->player)

From db100ff79d57c5871744b196e172e8a99acdab4f Mon Sep 17 00:00:00 2001
From: Dirk D <bluthund23@gmail.com>
Date: Thu, 18 Nov 2021 01:40:59 +0100
Subject: [PATCH 2/2] Align player kill count attribution with PrBoom+

This change breaks savegame compatibility by pulling in lastenemy field
from Boom.
---
 src/doom/p_inter.c | 21 ++++++++++++++++-----
 src/doom/p_mobj.c  |  2 ++
 src/doom/p_mobj.h  |  3 +++
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/doom/p_inter.c b/src/doom/p_inter.c
index 801175db8b..cbc1968a78 100644
--- a/src/doom/p_inter.c
+++ b/src/doom/p_inter.c
@@ -754,13 +754,20 @@ P_KillMobj
         {
             if (!deathmatch)
             {
-                // add kill to first player who is still ingame
-                for (unsigned int plridx = 0; plridx < MAXPLAYERS; plridx++)
+                if (target->lastenemy && target->lastenemy->health > 0 && target->lastenemy->player)
                 {
-                    if (playeringame[plridx])
+                    target->lastenemy->player->killcount++;
+                }
+                else
+                {
+                    // add kill to first player who is still ingame
+                    for (unsigned int plridx = 0; plridx < MAXPLAYERS; plridx++)
                     {
-                        players[plridx].killcount++;
-                        break;
+                        if (playeringame[plridx])
+                        {
+                            players[plridx].killcount++;
+                            break;
+                        }
                     }
                 }
             }
@@ -994,6 +1001,10 @@ P_DamageMobj
     {
 	// if not intent on another player,
 	// chase after this one
+        if ( !target->lastenemy || target->lastenemy->health <= 0
+             || !target->lastenemy->player)
+           target->lastenemy = target->target;
+
 	target->target = source;
 	target->threshold = BASETHRESHOLD;
 	if (target->state == &states[target->info->spawnstate]
diff --git a/src/doom/p_mobj.c b/src/doom/p_mobj.c
index 53a1d600d6..f3cf95b653 100644
--- a/src/doom/p_mobj.c
+++ b/src/doom/p_mobj.c
@@ -680,6 +680,8 @@ P_SpawnMobjSafe
     mobj->oldz = mobj->z;
     mobj->oldangle = mobj->angle;
 
+    mobj->lastenemy = NULL;
+
     // [crispy] height of the spawnstate's first sprite in pixels
     if (!info->actualheight)
     {
diff --git a/src/doom/p_mobj.h b/src/doom/p_mobj.h
index 87f1a25113..e00929829b 100644
--- a/src/doom/p_mobj.h
+++ b/src/doom/p_mobj.h
@@ -293,6 +293,9 @@ typedef struct mobj_s
     fixed_t		oldz;
     angle_t		oldangle;
 
+    // last known enemy
+    struct mobj_s*	lastenemy;
+
 } mobj_t;