miscellaneous fixes

code/lab/renderer/lab_renderer.cpp

@@ -422,6 +422,8 @@ void LabRenderer::useBackground(const SCP_string& mission_name) {
 		ltp_name = ltp::default_name();
 		if(optional_string("$Lighting Profile:")){
 			stuff_string(ltp_name,F_NAME);
+			if (ltp_name.empty())
+				ltp_name = ltp::default_name();
 		}
 		if (ltp_name != ltp::current()->name) {
 				ltp::switch_to(ltp_name);

code/mission/missionmessage.cpp

@@ -2647,8 +2647,13 @@ bool add_message(const char* name, const char* message, int persona_index, int m
 	strcpy_s(msg.message, message);
 	msg.persona_index = persona_index;
 	msg.multi_team = multi_team;
-	msg.avi_info.index = -1;
-	msg.wave_info.index = -1;
+	if (Fred_running) {
+		msg.avi_info.name = nullptr;
+		msg.wave_info.name = nullptr;
+	} else {
+		msg.avi_info.index = -1;
+		msg.wave_info.index = -1;
+	}
 	Messages.push_back(msg);
 	Num_messages++;
 

code/mission/missionparse.cpp

@@ -1002,6 +1002,8 @@ void parse_mission_info(mission *pm, bool basic = false)
 	if (optional_string("$Lighting Profile:"))
 	{
 		stuff_string(The_mission.lighting_profile_name, F_NAME);
+		if (The_mission.lighting_profile_name.empty())
+			The_mission.lighting_profile_name = lighting_profiles::default_name();
 	}
 	else
 		The_mission.lighting_profile_name = lighting_profiles::default_name();

code/mission/missionparse.h

@@ -208,8 +208,6 @@ typedef struct mission {
 	int		skybox_flags;
 	int		contrail_threshold;
 	int		ambient_light_level;
-	float	neb_far_multi;
-	float	neb_near_multi;
 	std::optional<volumetric_nebula> volumetrics;
 	sound_env	sound_environment;
 	vec3d   gravity;

code/missioneditor/missionsave.cpp

@@ -2977,7 +2977,7 @@ int Fred_mission_save::save_mission_info()
 	fso_comment_pop();
 
 	// EatThePath's lighting profiles
-	if (The_mission.lighting_profile_name != lighting_profiles::default_name()) {
+	if (!The_mission.lighting_profile_name.empty() && The_mission.lighting_profile_name != lighting_profiles::default_name()) {
 		fso_comment_push(";;FSO 23.1.0;;");
 		if (optional_string_fred("$Lighting Profile:")) {
 			parse_comments(2);