From c11645315860c53faf3646f1fc24f1aad4886939 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Thu, 7 Feb 2013 21:02:26 +0000
Subject: [PATCH] - When doing kickback in P_DamageMobj(), choose a random
 direction if the target and origin are in the exact same spot.

SVN r4069 (trunk)
---
 src/p_interaction.cpp | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/p_interaction.cpp b/src/p_interaction.cpp
index 3004022e47..51527a2661 100644
--- a/src/p_interaction.cpp
+++ b/src/p_interaction.cpp
@@ -66,6 +66,7 @@ static FRandom pr_damagemobj ("ActorTakeDamage");
 static FRandom pr_lightning ("LightningDamage");
 static FRandom pr_poison ("PoisonDamage");
 static FRandom pr_switcher ("SwitchTarget");
+static FRandom pr_kickbackdir ("KickbackDir");
 
 CVAR (Bool, cl_showsprees, true, CVAR_ARCHIVE)
 CVAR (Bool, cl_showmultikills, true, CVAR_ARCHIVE)
@@ -1073,9 +1074,18 @@ int P_DamageMobj (AActor *target, AActor *inflictor, AActor *source, int damage,
 		if (kickback)
 		{
 			AActor *origin = (source && (flags & DMG_INFLICTOR_IS_PUFF))? source : inflictor;
-			
-			ang = R_PointToAngle2 (origin->x, origin->y,
-				target->x, target->y);
+
+			// If the origin and target are in exactly the same spot, choose a random direction.
+			// (Most likely cause is from telefragging somebody during spawning because they
+			// haven't moved from their spawn spot at all.)
+			if (origin->x == target->x && origin->y == target->y)
+			{
+				ang = pr_kickbackdir.GenRand32();
+			}
+			else
+			{
+				ang = R_PointToAngle2 (origin->x, origin->y, target->x, target->y);
+			}
 
 			// Calculate this as float to avoid overflows so that the
 			// clamping that had to be done here can be removed.