sundry tweaks

- prevent infinite loop and warn when a game has no card fields
- choice fields are no longer ignored if they have no choices defined
- templates can now have the same name as their game folder (no hyphen needed)
- indent made by 4 spaces is now considered a tab (but will still produce a warning let's no kid ourselves)

data/en.mse-locale/locale

@@ -985,6 +985,7 @@ error:
 	images used for blending must have the same size:	Images used for blending must have the same size
 
 	# error from files
+	no card fields:						Game '%s' does not have any card fields. Define at least one card field.
 	no game specified:					No game specified for the %s
 	no stylesheet specified for the set:	No stylesheet specified for the set
 	stylesheet and set refer to different game:	

src/data/field/choice.cpp

@@ -39,7 +39,10 @@ IMPLEMENT_REFLECTION(ChoiceField) {
 }
 
 void ChoiceField::after_reading(Version ver) {
-  Field::after_reading(ver);
+  Field::after_reading(ver);
+  if (choices->choices.size() < 1) {
+    choices->choices.push_back(make_intrusive<Choice>(name));
+  }
   choices->initIds();
 }
 // ----------------------------------------------------------------------------- : ChoiceField::Choice

src/data/game.cpp

@@ -66,7 +66,11 @@ IMPLEMENT_REFLECTION(Game) {
   REFLECT_NO_SCRIPT(auto_replaces);
 }
 
-void Game::validate(Version v) {
+void Game::validate(Version v) {
+  // check that we have at least one card field
+  if (card_fields.size() < 1) {
+    throw Error(_ERROR_1_("no card fields", name()));
+  }
   Packaged::validate(v);
   // automatic statistics dimensions
   {

src/gui/new_window.cpp

@@ -78,7 +78,7 @@ void NewSetWindow::onGameSelect(wxCommandEvent&) {
   GameP game = game_list->getSelection<Game>(false);
   //handle_pending_errors(); // errors are ignored until set window is shown
   settings.default_game = game->name();
-  stylesheet_list->showData<StyleSheet>(game->name() + _("-*"));
+  stylesheet_list->showData<StyleSheet>(game->name() + _("*"));
   stylesheet_list->select(settings.gameSettingsFor(*game).default_stylesheet);
   UpdateWindowUI(wxUPDATE_UI_RECURSE);
   // resize (yuck)

src/util/io/reader.cpp

@@ -208,10 +208,10 @@ void Reader::readLine(bool in_string) {
   size_t pos = line.find_first_of(_(':'), indent);
   key = line.substr(indent, pos - indent);
   if (!ignore_invalid && !in_string && starts_with(key, _(" "))) {
-    warning(_("key: '") + key + _("' starts with a space; only use TABs for indentation!"), 0, false);
+    warning(String(_("key: '")) << key << _("' on line number ") << line_number << _(" starts with a space; only use TABs for indentation!"), 0, false);
-    // try to fix up: 8 spaces is a tab
+    // try to fix up: 4 spaces is a tab
-    while (starts_with(key, _("        "))) {
+    while (starts_with(key, _("    "))) {
-      key = key.substr(8);
+      key = key.substr(4);
       indent += 1;
     }
   }