warn on mismatched turret objects (#4458)

Author: Baezon

code/model/modelread.cpp

@@ -2385,26 +2385,29 @@ int read_model_file(polymodel * pm, const char *filename, int n_subsystems, mode
 				int n_banks = cfread_int(fp);			// Number of turrets
 
 				for ( i = 0; i < n_banks; i++ ) {
-					int parent;							// The parent subobj of the turret (the gun base)
-					int physical_parent;				// The subobj that the firepoints are physically attached to (the gun barrel)
 					int n_slots;						// How many firepoints the turret has
 					model_subsystem *subsystemp;		// The actual turret subsystem
 
-					parent = cfread_int( fp );
-					physical_parent = cfread_int(fp);
+					int base_obj = cfread_int(fp);		// The parent subobj of the turret (the gun base)
+					int gun_obj = cfread_int(fp);       // The subobj that the firepoints are physically attached to (the gun barrel)
+					
+					if (base_obj != gun_obj && pm->submodel[gun_obj].parent != base_obj) {
+						Warning(LOCATION, "Model %s turret %s has a gun submodel that is not an immediate child object of the base", pm->filename, pm->submodel[base_obj].name);
+						gun_obj = base_obj; // fall back to singlepart handling
+					}
 
 					int snum=-1;
 					if ( subsystems ) {
 						for ( snum = 0; snum < n_subsystems; snum++ ) {
 							subsystemp = &subsystems[snum];
 
-							if ( parent == subsystemp->subobj_num ) {
+							if ( base_obj == subsystemp->subobj_num ) {
 								cfread_vector( &temp_vec, fp );
 								vm_vec_normalize_safe(&temp_vec);
 								subsystemp->turret_norm = temp_vec;
 
 								n_slots = cfread_int( fp );
-								subsystemp->turret_gun_sobj = physical_parent;
+								subsystemp->turret_gun_sobj = gun_obj;
 								if(n_slots > MAX_TFP) {
 									Warning(LOCATION, "Model %s has %i turret firing points on subsystem %s, maximum is %i", pm->filename, n_slots, subsystemp->name, MAX_TFP);
 								}
@@ -2423,8 +2426,8 @@ int read_model_file(polymodel * pm, const char *filename, int n_subsystems, mode
 								subsystemp->turret_num_firing_points = n_slots;
 
 								// copy the subsystem index that the gun base submodel should have at this point
-								Assertion(pm->submodel[parent].subsys_num >= 0, "Turret gun base should have a subsystem index!");
-								pm->submodel[physical_parent].subsys_num = pm->submodel[parent].subsys_num;
+								Assertion(pm->submodel[base_obj].subsys_num >= 0, "Turret gun base should have a subsystem index!");
+								pm->submodel[gun_obj].subsys_num = pm->submodel[base_obj].subsys_num;
 
 								break;
 							}
@@ -2434,7 +2437,7 @@ int read_model_file(polymodel * pm, const char *filename, int n_subsystems, mode
 					if ( (n_subsystems == 0) || (snum == n_subsystems) ) {
 						vec3d bogus;
 
-						nprintf(("Warning", "Turret submodel %i not found for turret %i in model %s\n", parent, i, pm->filename));
+						nprintf(("Warning", "Turret submodel %i not found for turret %i in model %s\n", base_obj, i, pm->filename));
 						cfread_vector( &bogus, fp );
 						n_slots = cfread_int( fp );
 						for (j = 0; j < n_slots; j++ )