mission save compatibility

Make sure that missions without props will still be compatible with earlier mission file formats.  If props are included, bump the mission file version.  Also, fix some newline behavior in the save code.

Author: Goober5000

code/globalincs/utility.h

@@ -307,6 +307,13 @@ int count_items_with_field(const ITEM_T* item_array, int num_items, FIELD_T ITEM
 	return count;
 }
 
+template <typename VECTOR_T>
+size_t count_items_with_value(const VECTOR_T& item_vector)
+{
+	return std::count_if(item_vector.begin(), item_vector.end(),
+		[](const typename VECTOR_T::value_type& element) { return element.has_value(); });
+}
+
 template <typename VECTOR_T, typename ITEM_T, typename FIELD_T>
 int find_item_with_string(const VECTOR_T& item_vector, FIELD_T* ITEM_T::* field, const char* str)
 {

code/mission/missionparse.cpp

@@ -9422,3 +9422,8 @@ bool check_for_24_3_data()
 	}
 	return false;
 }
+
+bool check_for_25_1_data()
+{
+	return (count_items_with_value(Props) > 0);
+}

code/mission/missionparse.h

@@ -62,6 +62,7 @@ extern const gameversion::version LEGACY_MISSION_VERSION;
 extern bool check_for_23_3_data();
 extern bool check_for_24_1_data();
 extern bool check_for_24_3_data();
+extern bool check_for_25_1_data();
 
 #define WING_PLAYER_BASE	0x80000  // used by Fred to tell ship_index in a wing points to a player
 

code/missioneditor/missionsave.cpp

@@ -3032,10 +3032,16 @@ void Fred_mission_save::save_mission_internal(const char* pathname)
 	auto version_23_3 = gameversion::version(23, 3);
 	auto version_24_1 = gameversion::version(24, 1);
 	auto version_24_3 = gameversion::version(24, 3);
-	if (MISSION_VERSION >= version_24_3) {
+	auto version_25_1 = gameversion::version(25, 1);
+	if (MISSION_VERSION >= version_25_1) {
 		Warning(LOCATION,
-			"Notify an SCP coder: now that the required mission version is at least 24.3, the check_for_24_3_data(), "
-			"the check_for_24_1_data() and check_for_23_3_data() code can be removed");
+			"Notify an SCP coder: now that the required mission version is at least 25.1, the check_for_25_1_data(), "
+			"check_for_24_3_data(), check_for_24_1_data(), and check_for_23_3_data() code can be removed");
+	} else if (check_for_25_1_data()) {
+		The_mission.required_fso_version = version_25_1;
+	} else if (MISSION_VERSION >= version_24_3) {
+		Warning(LOCATION, "Notify an SCP coder: now that the required mission version is at least 24.3, the "
+			"check_for_24_3_data(), check_for_24_1_data(), and check_for_23_3_data() code can be removed");
 	} else if (check_for_24_3_data()) {
 		The_mission.required_fso_version = version_24_3;
 	} else if (MISSION_VERSION >= version_24_1) {
@@ -3382,7 +3388,7 @@ int Fred_mission_save::save_warp_params(WarpDirection direction, ship* shipp)
 int Fred_mission_save::save_objects()
 {
 	SCP_string sexp_out;
-	int i, z;
+	int i, z, count;
 	object* objp;
 	ship* shipp;
 	ship_info* sip;
@@ -3391,7 +3397,7 @@ int Fred_mission_save::save_objects()
 	parse_comments(2);
 	fout("\t\t;! %d total\n", ship_get_num_ships());
 
-	for (i = z = 0; i < MAX_SHIPS; i++) {
+	for (i = count = 0; i < MAX_SHIPS; i++) {
 		if (Ships[i].objnum < 0) {
 			continue;
 		}
@@ -3406,9 +3412,11 @@ int Fred_mission_save::save_objects()
 		sip = &Ship_info[shipp->ship_info_index];
 		required_string_either_fred("$Name:", "#Wings");
 		required_string_fred("$Name:");
-		parse_comments(z ? 2 : 1);
+		parse_comments(count ? 2 : 1);
 		fout(" %s\t\t;! Object #%d", shipp->ship_name, i);
 
+		count++;
+
 		// Display name
 		// The display name is only written if there was one at the start to avoid introducing inconsistencies
 		if (save_config.save_format != MissionFormat::RETAIL && ((save_config.always_save_display_names && shipp->wingnum < 0) || shipp->has_display_name())) {
@@ -4153,8 +4161,6 @@ int Fred_mission_save::save_objects()
 
 		// end of texture replacement -------------------------------
 
-		z++;
-
 		fso_comment_pop();
 	}
 
@@ -4855,18 +4861,19 @@ int Fred_mission_save::save_wings()
 	fred_parse_flag = 0;
 	required_string_fred("#Wings");
 	parse_comments(2);
-	fout("\t\t;! %d total", Num_wings);
+	fout("\t\t;! %d total\n", Num_wings);
 
 	for (auto& w : Wings) {
 		if (!w.wave_count)
 			continue;
 
-		count++;
 		required_string_one_of_fred(3, "$Name:", "#Events", "#Props");
 		required_string_fred("$Name:");
-		parse_comments(2);
+		parse_comments(count ? 2 : 1);
 		fout(" %s", w.name);
 
+		count++;
+
 		// squad logo - Goober5000
 		if (save_config.save_format != MissionFormat::RETAIL) {
 			if (strlen(w.wing_squad_filename) > 0) //-V805
@@ -5124,21 +5131,30 @@ int Fred_mission_save::save_wings()
 
 int Fred_mission_save::save_props()
 {
-	if (save_config.save_format != MissionFormat::RETAIL) {
+	auto num_props = count_items_with_value(Props);
+
+	if ((save_config.save_format != MissionFormat::RETAIL) && (num_props > 0)) {
 		fred_parse_flag = 0;
-		required_string_fred("#Props");
-		parse_comments(2);
-		fout("\t\t;! %d total", static_cast<int>(Props.size()));
+		size_t count = 0;
+
+		if (optional_string_fred("#Props", "#End")) {
+			parse_comments(2);
+		} else {
+			fout("\n\n#Props");
+		}
+		fout("\t\t;! " SIZE_T_ARG " total\n", num_props);
 
 		for (const auto& p : Props) {
 			if (p.has_value()) {
 				required_string_either_fred("$Name:", "#Events");
 				required_string_fred("$Name:");
-				parse_comments(2);
+				parse_comments(count ? 2 : 1);
 				fout(" %s", p->prop_name);
 
-				required_string_fred("$Class:");
-				parse_comments(2);
+				count++;
+
+				required_string_fred("\n$Class:");
+				parse_comments(0);
 				fout(" %s", Prop_info[p->prop_info_index].name.c_str());
 
 				required_string_fred("$Location:");