Server: Add cvar 'mp_foosteps', which only works in multiplayer. Hence the name.

src/server/footsteps.qc

@@ -264,6 +264,11 @@ Footsteps_Update(void)
 {
 	NSClientPlayer pl;
 
+	/* mp_footsteps is only available in MP matches */
+	if (Util_IsSingleplayer() == false)
+		if (autocvar(mp_footsteps, 1) == 0)
+			return;
+
 	if (self.classname != "player")
 		return;
 

src/shared/defs.h

@@ -298,3 +298,20 @@ string Util_FixModel(string mdl)
 
 	return mdl;
 }
+
+bool
+Util_IsSingleplayer(void)
+{
+#ifdef SERVER
+	/* playerslots 1 is always singleplayer */
+	if (cvar("sv_playerslots") == 1)
+		return true;
+
+	/* only when coop is 1, only in multiplayer */
+	if (cvar("coop") == 1 && cvar("sv_playerslots") > 1)
+		return true;
+#endif
+
+	/* else we're multiplayer */
+	return false;
+}