diff --git a/src/p_interaction.cpp b/src/p_interaction.cpp
index a16069c7b..74bfc56f4 100644
--- a/src/p_interaction.cpp
+++ b/src/p_interaction.cpp
@@ -950,6 +950,8 @@ int P_DamageMobj (AActor *target, AActor *inflictor, AActor *source, int damage,
 	int fakeDamage = 0;
 	int holdDamage = 0;
 	
+	if (damage < 0) damage = 0;
+
 	if (target == NULL || !((target->flags & MF_SHOOTABLE) || (target->flags6 & MF6_VULNERABLE)))
 	{ // Shouldn't happen
 		return -1;
@@ -1038,6 +1040,7 @@ int P_DamageMobj (AActor *target, AActor *inflictor, AActor *source, int damage,
 			// Invulnerable, and won't wake up
 			return -1;
 		}
+
 		if (damage < TELEFRAG_DAMAGE) // TELEFRAG_DAMAGE may not be reduced at all or it may not guarantee its effect.
 		{
 			player = target->player;
@@ -1116,6 +1119,10 @@ int P_DamageMobj (AActor *target, AActor *inflictor, AActor *source, int damage,
 					return -1;
 				}
 			}
+			if (target->flags5 & MF5_NODAMAGE)
+			{
+				damage = 0;
+			}
 		}
 	}
 	if (damage < 0)
diff --git a/src/p_map.cpp b/src/p_map.cpp
index f858b8a4a..2362fbd12 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -4790,7 +4790,7 @@ void P_RadiusAttack(AActor *bombspot, AActor *bombsource, int bombdamage, int bo
 			points *= thing->GetClass()->Meta.GetMetaFixed(AMETA_RDFactor, FRACUNIT) / (double)FRACUNIT;
 
 			// points and bombdamage should be the same sign
-			if (((bombspot->flags7 & MF7_CAUSEPAIN) || (points * bombdamage) > 0) && P_CheckSight(thing, bombspot, SF_IGNOREVISIBILITY | SF_IGNOREWATERBOUNDARY))
+			if (((points * bombdamage) > 0) && P_CheckSight(thing, bombspot, SF_IGNOREVISIBILITY | SF_IGNOREWATERBOUNDARY))
 			{ // OK to damage; target is in direct path
 				double velz;
 				double thrust;
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 23fb9cf3c..c12bd53db 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -6159,11 +6159,6 @@ int AActor::TakeSpecialDamage (AActor *inflictor, AActor *source, int damage, FN
 {
 	FState *death;
 
-	if (flags5 & MF5_NODAMAGE)
-	{
-		return 0;
-	}
-
 	// If the actor does not have a corresponding death state, then it does not take damage.
 	// Note that DeathState matches every kind of damagetype, so an actor has that, it can
 	// be hurt with any type of damage. Exception: Massacre damage always succeeds, because
diff --git a/src/r_swrenderer.cpp b/src/r_swrenderer.cpp
index fb54b6f0a..df928b25e 100644
--- a/src/r_swrenderer.cpp
+++ b/src/r_swrenderer.cpp
@@ -84,7 +84,7 @@ void FSoftwareRenderer::PrecacheTexture(FTexture *tex, int cache)
 {
 	if (tex != NULL)
 	{
-		if (cache & 1)
+		if (cache & FTextureManager::HIT_Columnmode)
 		{
 			const FTexture::Span *spanp;
 			tex->GetColumn(0, &spanp);
diff --git a/src/textures/texturemanager.cpp b/src/textures/texturemanager.cpp
index fe01f13a5..83eda0bb6 100644
--- a/src/textures/texturemanager.cpp
+++ b/src/textures/texturemanager.cpp
@@ -1248,7 +1248,7 @@ void FTextureManager::PrecacheLevel (void)
 
 	for (unsigned i = 0; i < level.info->PrecacheTextures.Size(); i++)
 	{
-		hitlist[level.info->PrecacheTextures[i].GetIndex()] |= 1;
+		hitlist[level.info->PrecacheTextures[i].GetIndex()] |= FTextureManager::HIT_Wall;
 	}
 
 	for (int i = cnt - 1; i >= 0; i--)
diff --git a/src/textures/textures.h b/src/textures/textures.h
index c6eedfb83..6192da835 100644
--- a/src/textures/textures.h
+++ b/src/textures/textures.h
@@ -433,6 +433,16 @@ public:
 		TEXMAN_DontCreate = 32
 	};
 
+	enum
+	{
+		HIT_Wall = 1,
+		HIT_Flat = 2,
+		HIT_Sky = 4,
+		HIT_Sprite = 8,
+
+		HIT_Columnmode = HIT_Wall|HIT_Sky|HIT_Sprite
+	};
+
 	FTextureID CheckForTexture (const char *name, int usetype, BITFIELD flags=TEXMAN_TryAny);
 	FTextureID GetTexture (const char *name, int usetype, BITFIELD flags=0);
 	int ListTextures (const char *name, TArray<FTextureID> &list);
diff --git a/src/v_video.cpp b/src/v_video.cpp
index e70c72cfd..aaf1aec3d 100644
--- a/src/v_video.cpp
+++ b/src/v_video.cpp
@@ -1245,7 +1245,7 @@ void DFrameBuffer::GetHitlist(BYTE *hitlist)
 					FTextureID pic = frame->Texture[k];
 					if (pic.isValid())
 					{
-						hitlist[pic.GetIndex()] = 5;
+						hitlist[pic.GetIndex()] = HIT_Sprite;
 					}
 				}
 			}
@@ -1257,14 +1257,14 @@ void DFrameBuffer::GetHitlist(BYTE *hitlist)
 	for (i = numsectors - 1; i >= 0; i--)
 	{
 		hitlist[sectors[i].GetTexture(sector_t::floor).GetIndex()] = 
-			hitlist[sectors[i].GetTexture(sector_t::ceiling).GetIndex()] |= 2;
+			hitlist[sectors[i].GetTexture(sector_t::ceiling).GetIndex()] |= HIT_Flat;
 	}
 
 	for (i = numsides - 1; i >= 0; i--)
 	{
 		hitlist[sides[i].GetTexture(side_t::top).GetIndex()] =
 		hitlist[sides[i].GetTexture(side_t::mid).GetIndex()] =
-		hitlist[sides[i].GetTexture(side_t::bottom).GetIndex()] |= 3;
+		hitlist[sides[i].GetTexture(side_t::bottom).GetIndex()] |= HIT_Wall;
 	}
 
 	// Sky texture is always present.
@@ -1276,11 +1276,11 @@ void DFrameBuffer::GetHitlist(BYTE *hitlist)
 
 	if (sky1texture.isValid())
 	{
-		hitlist[sky1texture.GetIndex()] |= 3;
+		hitlist[sky1texture.GetIndex()] |= HIT_Sky;
 	}
 	if (sky2texture.isValid())
 	{
-		hitlist[sky2texture.GetIndex()] |= 3;
+		hitlist[sky2texture.GetIndex()] |= HIT_Sky;
 	}
 }
 
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index d85717ead..7d8fad5bf 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -325,7 +325,7 @@ ACTOR Actor native //: Thinker
 	action native A_GiveToSiblings(class<Inventory> itemtype, int amount = 0);
 	action native A_TakeFromChildren(class<Inventory> itemtype, int amount = 0);
 	action native A_TakeFromSiblings(class<Inventory> itemtype, int amount = 0);
-	action native A_SetTeleFog(class<TeleportFog> oldpos, class<TeleportFog> newpos);
+	action native A_SetTeleFog(class<Actor> oldpos, class<Actor> newpos);
 	action native A_SwapTeleFog();
 	action native A_SetFloatBobPhase(int bob);
 	action native A_SetHealth(int health, int ptr = AAPTR_DEFAULT);