- added MF5_NOFORWARDFALL flag to prevent attacks from making its victim fall forward randomly.

src/actor.h

@@ -268,7 +268,7 @@ enum
 	MF5_DONTDRAIN		= 0x00000001,	// cannot be drained health from.
 	/*					= 0x00000002,	*/
 	MF5_NODROPOFF		= 0x00000004,	// cannot drop off under any circumstances.
-	/*					= 0x00000008,	*/
+	MF5_NOFORWARDFALL	= 0x00000008,	// Does not make any actor fall forward by being damaged by this
 	MF5_COUNTSECRET		= 0x00000010,	// From Doom 64: actor acts like a secret
 	MF5_AVOIDINGDROPOFF = 0x00000020,	// Used to move monsters away from dropoffs
 	MF5_NODAMAGE		= 0x00000040,	// Actor can be shot and reacts to being shot but takes no damage

src/p_interaction.cpp

@@ -1143,7 +1143,9 @@ int P_DamageMobj (AActor *target, AActor *inflictor, AActor *source, int damage,
 				 && (pr_damagemobj()&1)
 				 // [RH] But only if not too fast and not flying
 				 && thrust < 10*FRACUNIT
-				 && !(target->flags & MF_NOGRAVITY))
+				 && !(target->flags & MF_NOGRAVITY)
+				 && (inflictor == NULL || !(inflictor->flags5 & MF5_NOFORWARDFALL))
+				 )
 			{
 				ang += ANG180;
 				thrust *= 4;

src/thingdef/thingdef_data.cpp

@@ -184,6 +184,7 @@ static FFlagDef ActorFlags[]=
 
 	DEFINE_FLAG(MF5, DONTDRAIN, AActor, flags5),
 	DEFINE_FLAG(MF5, NODROPOFF, AActor, flags5),
+	DEFINE_FLAG(MF5, NOFORWARDFALL, AActor, flags5),
 	DEFINE_FLAG(MF5, COUNTSECRET, AActor, flags5),
 	DEFINE_FLAG(MF5, NODAMAGE, AActor, flags5),
 	DEFINE_FLAG(MF5, BLOODSPLATTER, AActor, flags5),