Add sv_gameplayfix_elevators cvar

If an entity is standing on a platform and gets blocked by it,
try nudging it up a bit first to get it unstuck.

Cvar values:
0 = no fix (vanilla behavior)
1 = fix players only
2 = fix all entities (default)

Quake/sv_main.c

@@ -156,6 +156,7 @@ void SV_Init (void)
 	extern	cvar_t	sv_aim;
 	extern	cvar_t	sv_altnoclip; //johnfitz
 	extern	cvar_t	sv_gameplayfix_random;
+	extern	cvar_t	sv_gameplayfix_elevators;
 	extern	cvar_t	sv_autoload;
 	extern	cvar_t	sv_autosave;
 	extern	cvar_t	sv_autosave_interval;
@@ -177,6 +178,7 @@ void SV_Init (void)
 	Cvar_RegisterVariable (&pr_checkextension);
 	Cvar_RegisterVariable (&sv_altnoclip); //johnfitz
 	Cvar_RegisterVariable (&sv_gameplayfix_random);
+	Cvar_RegisterVariable (&sv_gameplayfix_elevators);
 	Cvar_RegisterVariable (&sv_netsort);
 	Cvar_RegisterVariable (&sv_autoload);
 	Cvar_RegisterVariable (&sv_autosave);

Quake/sv_phys.c

@@ -430,6 +430,7 @@ trace_t SV_PushEntity (edict_t *ent, vec3_t push)
 SV_PushMove
 ============
 */
+cvar_t sv_gameplayfix_elevators = {"sv_gameplayfix_elevators", "2", CVAR_ARCHIVE}; // 0=off; 1=clients only; 2=all entities
 void SV_PushMove (edict_t *pusher, float movetime)
 {
 	int			i, e;
@@ -473,6 +474,7 @@ void SV_PushMove (edict_t *pusher, float movetime)
 	check = NEXT_EDICT(qcvm->edicts);
 	for (e=1 ; e<qcvm->num_edicts ; e++, check = NEXT_EDICT(check))
 	{
+		qboolean riding;
 		if (check->free)
 			continue;
 		if (check->v.movetype == MOVETYPE_PUSH
@@ -495,7 +497,11 @@ void SV_PushMove (edict_t *pusher, float movetime)
 		// see if the ent's bbox is inside the pusher's final position
 			if (!SV_TestEntityPosition (check))
 				continue;
+
+			riding = false;
 		}
+		else
+			riding = true;
 
 	// remove the onground flag for non-players
 		if (check->v.movetype != MOVETYPE_WALK)
@@ -524,6 +530,16 @@ void SV_PushMove (edict_t *pusher, float movetime)
 				continue;
 			}
 
+			// try moving the entity up a bit if it's blocked by the pusher while also standing on it
+			if (riding && block == pusher &&
+				(sv_gameplayfix_elevators.value >= 2.f ||
+				(sv_gameplayfix_elevators.value && e <= svs.maxclients)))
+			{
+				check->v.origin[2] += DIST_EPSILON;
+				if (!SV_TestEntityPosition (check))
+					continue;
+			}
+
 			VectorCopy (entorig, check->v.origin);
 			SV_LinkEdict (check, true);
 

Quake/world.c

@@ -618,7 +618,7 @@ edict_t	*SV_TestEntityPosition (edict_t *ent)
 	trace = SV_Move (ent->v.origin, ent->v.mins, ent->v.maxs, ent->v.origin, 0, ent);
 
 	if (trace.startsolid)
-		return qcvm->edicts;
+		return trace.ent ? trace.ent : qcvm->edicts;
 
 	return NULL;
 }