(svn r16936) -Fix [FS#3053]: Rail station build window with NewGRFs could crash due to uninitialized string parameter.

src/rail_gui.cpp

@@ -1050,7 +1050,6 @@ public:
 			}
 		}
 
-		SetDParam(0, GetStationClassName(_railstation.station_class));
 		this->DrawWidgets();
 
 		/* 'Accepts' and 'Supplies' texts. */
@@ -1066,6 +1065,21 @@ public:
 		}
 	}
 
+	virtual void UpdateWidgetSize(int widget, Dimension *size, const Dimension &padding, Dimension *resize)
+	{
+		if (widget != BRSW_NEWST_DROPDOWN) return;
+
+		Dimension d = {0, 0};
+		for (uint i = 0; i < GetNumStationClasses(); i++) {
+			if (i == STAT_CLASS_WAYP) continue;
+			SetDParam(0, GetStationClassName((StationClassID)i));
+			d = maxdim(d, GetStringBoundingBox(STR_BLACK_STRING));
+		}
+		d.width += padding.width;
+		d.height += padding.height;
+		*size = maxdim(*size, d);
+	}
+
 	virtual void DrawWidget(const Rect &r, int widget) const
 	{
 		DrawPixelInfo tmp_dpi;
@@ -1114,6 +1128,11 @@ public:
 				}
 				break;
 			}
+
+			case BRSW_NEWST_DROPDOWN:
+				SetDParam(0, GetStationClassName(_railstation.station_class));
+				DrawString(r.left + WD_DROPDOWNTEXT_LEFT, r.right - WD_DROPDOWNTEXT_RIGHT, r.top + WD_DROPDOWNTEXT_TOP, STR_BLACK_STRING, TC_BLACK);
+				break;
 		}
 	}
 
@@ -1353,7 +1372,7 @@ static const NWidgetPart _nested_newstation_builder_widgets[] = {
 	NWidget(WWT_PANEL, COLOUR_DARK_GREEN, BRSW_BACKGROUND),
 		/* begin newstations gui additions. */
 		NWidget(NWID_SPACER), SetMinimalSize(0, 3),
-		NWidget(WWT_DROPDOWN, COLOUR_GREY, BRSW_NEWST_DROPDOWN), SetMinimalSize(134, 12), SetPadding(0, 7, 0, 7), SetDataTip(STR_BLACK_STRING, STR_SELECT_STATION_CLASS_TIP),
+		NWidget(WWT_DROPDOWN, COLOUR_GREY, BRSW_NEWST_DROPDOWN), SetMinimalSize(134, 12), SetPadding(0, 7, 0, 7), SetDataTip(STR_EMPTY, STR_SELECT_STATION_CLASS_TIP),
 		NWidget(NWID_SPACER), SetMinimalSize(0, 3),
 		NWidget(NWID_HORIZONTAL), SetPIP(7, 0, 7),
 			NWidget(WWT_MATRIX, COLOUR_GREY, BRSW_NEWST_LIST), SetMinimalSize(122, 71), SetDataTip(0x501, STR_SELECT_STATION_TYPE_TIP),