Add extra layers of try-catch for the unlikely of an exception while …

…showing an error.

src/gui/dialogs/wml_error.cpp

@@ -171,6 +171,39 @@ namespace dialogs
 
 REGISTER_DIALOG(wml_error)
 
+static void display_error_in_error(const std::string& title, const std::string& original_error, const std::string& error_in_error)
+{
+	std::string message = original_error;
+	message += "\n\n";
+	message += _("Additionally, the following error was encountered while handling this error:");
+	message += "\n\n";
+	message += error_in_error;
+	message += "\n\n";
+	message += _("Due to this subsequent error, the game will now exit.");
+	SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, title.c_str(), message.c_str(), nullptr);
+}
+
+void wml_error::display(const std::string& summary,
+					const std::string& post_summary,
+					const std::vector<std::string>& files,
+					const std::string& details)
+{
+	bool have_error = false;
+	try {
+		wml_error error_dialog(summary, post_summary, files, details);
+		try {
+			error_dialog.show();
+		} catch(std::exception& error) {
+			have_error = true;
+			display_error_in_error("WML Error", error_dialog.report_, error.what());
+			throw;
+		}
+	} catch(std::exception& error) {
+		if(!have_error) display_error_in_error("WML Error", summary, error.what());
+		throw;
+	}
+}
+
 wml_error::wml_error(const std::string& summary,
 					   const std::string& post_summary,
 					   const std::vector<std::string>& files,

src/gui/dialogs/wml_error.hpp

@@ -43,10 +43,7 @@ class wml_error : public modal_dialog
 	static void display(const std::string& summary,
 						const std::string& post_summary,
 						const std::vector<std::string>& files,
-						const std::string& details)
-	{
-		wml_error(summary, post_summary, files, details).show();
-	}
+						const std::string& details);
 
 	/** The display function; see @ref modal_dialog for more information. */
 	static void display(const std::string& summary,