Merge branch 'master' of git://github.com/wesnoth/wesnoth

changelog

@@ -190,6 +190,8 @@ Version 1.13.0-dev:
    * Wesnoth reports an error if it evalutes [if] and finds no [then], [else], [elseif]
      children, as a chat message from lua.
    * Fix bug #22134: Campaign prefix not used in mp campaign saves
+   * Made the error messages sent to stderr when the core data dir is
+     incorrectly set more helpful.
 
 Version 1.11.11:
  * Add-ons server:

src/font.cpp

@@ -1258,7 +1258,13 @@ bool load_font_config()
 	//config when changing languages
 	config cfg;
 	try {
-		scoped_istream stream = preprocess_file(get_wml_location("hardwired/fonts.cfg"));
+		const std::string& cfg_path = get_wml_location("hardwired/fonts.cfg");
+		if(cfg_path.empty()) {
+			ERR_FT << "could not resolve path to fonts.cfg, file not found\n";
+			return false;
+		}
+
+		scoped_istream stream = preprocess_file(cfg_path);
 		read(cfg, *stream);
 	} catch(config::error &e) {
 		ERR_FT << "could not read fonts.cfg:\n"

src/game.cpp

@@ -419,6 +419,24 @@ static void init_locale() {
 	textdomain (PACKAGE);
 }
 
+/**
+ * Print an alert and instructions to stderr about early initialization errors.
+ *
+ * This is provided as an aid for users dealing with potential data dir
+ * configuration issues. The first code to read core WML *has* the
+ * responsibility to call this function in the event of a problem, to inform
+ * the user of the most likely possible cause and suggest a course of action
+ * to solve the issue.
+ */
+static void warn_early_init_failure()
+{
+	// NOTE: wrap output to 80 columns.
+	std::cerr << '\n'
+			  << "An error at this point during initialization usually indicates that the data\n"
+			  << "directory above was not correctly set or detected. Try passing the correct path\n"
+			  << "in the command line with the --config-dir switch or as the only argument.\n";
+}
+
 /**
  * Setups the game environment and enters
  * the titlescreen or game loops.
@@ -448,6 +466,8 @@ static int do_gameloop(int argc, char** argv)
 	res = font::load_font_config();
 	if(res == false) {
 		std::cerr << "could not initialize fonts\n";
+		// The most common symptom of a bogus data dir path -- warn the user.
+		warn_early_init_failure();
 		return 1;
 	}