(svn r26652) [1.4] -Backport from trunk:

- Fix: Segmentation fault when encountering a .obg/.obs/.obm with empty string/zero length MD5 checksums [FS#6038] (r26637)
- Fix: The 'Load' button was not properly enabled/disabled for old savegames without NewGRF information (r26634)
- Fix: If the video driver fails to supply a list of resolutions, display an error message [FS#6012] (r26629)

src/settings_gui.cpp

@@ -269,6 +269,8 @@ struct GameOptionsWindow : Window {
 			}
 
 			case WID_GO_RESOLUTION_DROPDOWN: // Setup resolution dropdown
+				if (_num_resolutions == 0) break;
+
 				list = new DropDownList();
 				*selected_index = GetCurRes();
 				for (int i = 0; i < _num_resolutions; i++) {
@@ -466,6 +468,8 @@ struct GameOptionsWindow : Window {
 				DropDownList *list = this->BuildDropDownList(widget, &selected);
 				if (list != NULL) {
 					ShowDropDownList(this, list, selected, widget);
+				} else {
+					if (widget == WID_GO_RESOLUTION_DROPDOWN) ShowErrorMessage(STR_ERROR_RESOLUTION_LIST_FAILED, INVALID_STRING_ID, WL_ERROR);
 				}
 				break;
 			}