(svn r12904) -Fix [FS#1953]: remove trams from savegames saved in OTTD without tram support, it is better than to simply crash

3 files changed, 18 insertions, 1 deletions

diff --git a/src/lang/english.txt b/src/lang/english.txt
index 165a3c618..972666cc3 100644
--- a/src/lang/english.txt
+++ b/src/lang/english.txt
@@ -3182,6 +3182,8 @@ STR_NEWGRF_NOT_FOUND_WARNING                                    :{WHITE}Missing
 STR_NEWGRF_UNPAUSE_WARNING_TITLE                                :{YELLOW}Missing GRF file(s)
 STR_NEWGRF_UNPAUSE_WARNING                                      :{WHITE}Unpausing can crash OpenTTD. Do not file bug reports for subsequent crashes.{}Do you really want to unpause?
 
+STR_LOADGAME_REMOVED_TRAMS                                      :{WHITE}Game was saved in version without tram support. All trams have been removed.
+
 STR_CURRENCY_WINDOW                                             :{WHITE}Custom currency
 STR_CURRENCY_EXCHANGE_RATE                                      :{LTBLUE}Exchange rate: {ORANGE}{CURRENCY} = £ {COMMA}
 STR_CURRENCY_SEPARATOR                                          :{LTBLUE}Separator:
diff --git a/src/openttd.cpp b/src/openttd.cpp
index 2d32c04f6..50bf799c7 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -2501,6 +2501,21 @@ bool AfterLoadGame()
 		}
 	}
 
+	if (CheckSavegameVersion(62)) {
+		/* Remove all trams from savegames without tram support.
+		 * There would be trams without tram track under causing crashes sooner or later. */
+		Vehicle *v;
+		FOR_ALL_VEHICLES(v) {
+			if (v->type == VEH_ROAD && v->First() == v &&
+					HasBit(EngInfo(v->engine_type)->misc_flags, EF_ROAD_TRAM)) {
+				if (_switch_mode_errorstr == INVALID_STRING_ID || _switch_mode_errorstr == STR_NEWGRF_COMPATIBLE_LOAD_WARNING) {
+					_switch_mode_errorstr = STR_LOADGAME_REMOVED_TRAMS;
+				}
+				delete v;
+			}
+		}
+	}
+
 	return InitializeWindowsAndCaches();
 }
 
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index d8acda4ab..ec4908669 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -591,7 +591,7 @@ void Vehicle::PreDestructor()
 	}
 
 	Window *w = FindWindowById(WC_MAIN_WINDOW, 0);
-	if (WP(w, vp_d).follow_vehicle == this->index) {
+	if (w != NULL && WP(w, vp_d).follow_vehicle == this->index) {
 		ScrollMainWindowTo(this->x_pos, this->y_pos, true); // lock the main view on the vehicle's last position
 		WP(w, vp_d).follow_vehicle = INVALID_VEHICLE;
 	}