Fixes a potential map crash for atcommand mapflag (#6255)

* Fixes #6254.
* Adds a few checks for MF_RESTRICTED so the status is not disabled if other zones are active for the same map.
Thanks to @xEasycore and @Lemongrass3110!

src/map/atcommand.cpp

@@ -8418,7 +8418,7 @@ ACMD_FUNC(mapflag) {
 												MF_SKILL_DAMAGE,
 												MF_SKILL_DURATION };
 
-			if (flag && std::find(disabled_mf.begin(), disabled_mf.end(), mapflag) != disabled_mf.end()) {
+			if (flag > 0 && util::vector_exists(disabled_mf, mapflag)) {
 				sprintf(atcmd_output,"[ @mapflag ] %s flag cannot be enabled as it requires unique values.", flag_name);
 				clif_displaymessage(sd->fd,atcmd_output);
 			} else {

src/map/map.cpp

@@ -4745,13 +4745,23 @@ bool map_setmapflag_sub(int16 m, enum e_mapflag mapflag, bool status, union u_ma
 			mapdata->flag[mapflag] = status;
 			break;
 		case MF_RESTRICTED:
-			nullpo_retr(false, args);
+			if (!status) {
+				if (args == nullptr) {
+					mapdata->zone = 0;
+				} else {
+					mapdata->zone ^= (1 << (args->flag_val + 1)) << 3;
+				}
+
+				// Don't completely disable the mapflag's status if other zones are active
+				if (mapdata->zone == 0) {
+					mapdata->flag[mapflag] = status;
+				}
+			} else {
+				nullpo_retr(false, args);
 
-			mapdata->flag[mapflag] = status;
-			if (!status)
-				mapdata->zone ^= (1 << (args->flag_val + 1)) << 3;
-			else
 				mapdata->zone |= (1 << (args->flag_val + 1)) << 3;
+				mapdata->flag[mapflag] = status;
+			}
 			break;
 		case MF_NOCOMMAND:
 			if (status) {