clean up check_sexp_syntax and improve caching

code/mission/missionparse.cpp

@@ -178,6 +178,9 @@ SCP_vector<SCP_string> Parse_names;
 
 SCP_vector<SCP_string> Mission_parse_warnings;
 
+// true while a mission is being parsed and post-processed
+bool Parsing_mission = false;
+
 // Routes a parse-time auto-correction notice to the right surface for the app:
 // outside QtFRED, the existing Warning(LOCATION, ...) popup; inside QtFRED, the
 // Mission_parse_warnings queue so the ErrorChecker can present it without a popup.
@@ -7552,6 +7555,8 @@ bool parse_main(const char *mission_name, int flags)
 
 	Assert(Ship_info.size() <= MAX_SHIP_CLASSES);
 
+	Parsing_mission = true;
+
 	do {
 		// don't do this for imports
 		if (!(flags & MPF_IMPORT_FSM)) {
@@ -7603,6 +7608,8 @@ bool parse_main(const char *mission_name, int flags)
 		}
 	} while (0);
 
+	Parsing_mission = false;
+
 	if (!Fred_running)
 		strcpy_s(Mission_filename, mission_name);
 

code/mission/missionparse.h

@@ -588,6 +588,9 @@ extern SCP_vector<SCP_string> Parse_names;
 // silently buried. Outside of QtFRED these sites still call Warning(LOCATION, ...).
 extern SCP_vector<SCP_string> Mission_parse_warnings;
 
+// true while a mission is being parsed and post-processed
+extern bool Parsing_mission;
+
 extern char			Player_start_shipname[NAME_LENGTH];
 extern int			Player_start_shipnum;
 extern p_object	*Player_start_pobject;

code/missionui/redalert.cpp

@@ -969,9 +969,8 @@ void red_alert_bash_ship_status()
 					// give the ship its name from the latest wave
 					// (this will make the ship match to the correct red-alert data)
 					wing_bash_ship_name(shipp, wingp, ((rws->latest_wave - 1) * wingp->wave_count) + 1 + pos_in_wing);
-					// need to update the ship registry too
-					strcpy_s(Ship_registry[ship_entry_index].name, shipp->ship_name);
-					Ship_registry_map[shipp->ship_name] = ship_entry_index;
+					// need to update the ship registry too; keep the old key because the previous name was a real ship name that may still be referenced
+					ship_registry_rename(ship_entry_index, shipp->ship_name, false);
 				}
 			}
 		}

code/network/multi_ingame.cpp

@@ -1332,7 +1332,12 @@ void process_ingame_wings_packet( ubyte *data, header *hinfo )
 				// kind of stupid, but bash the name since it won't get recreated properly from
 				// the parse_wing_create_ships call.
 				shipp = &Ships[shipnum];
+				int ship_entry_index = ship_registry_get_index(shipp->ship_name);
+				Assertion(ship_entry_index >= 0, "Ship %s must be in the ship registry!", shipp->ship_name);
 				wing_bash_ship_name(shipp, wingp, which_one + 1);
+				// need to update the ship registry too
+				if (ship_entry_index >= 0)
+					ship_registry_rename(ship_entry_index, shipp->ship_name, true);
 				nprintf(("Network", "Created %s\n", shipp->ship_name));
 
 				objp = &Objects[shipp->objnum];