input_plugin: method init() returns errors with GError

Not used by any plugin currently, but this eliminates the g_error()
call in input_plugin_config(), so it's worth it.

src/input/curl_input_plugin.c

@@ -104,7 +104,8 @@ static const char *proxy, *proxy_user, *proxy_password;
 static unsigned proxy_port;
 
 static bool
-input_curl_init(const struct config_param *param)
+input_curl_init(const struct config_param *param,
+		G_GNUC_UNUSED GError **error_r)
 {
 	CURLcode code = curl_global_init(CURL_GLOBAL_ALL);
 	if (code != CURLE_OK) {

src/input_init.c

@@ -22,9 +22,16 @@
 #include "input_plugin.h"
 #include "input_registry.h"
 #include "conf.h"
+#include "glib_compat.h"
 
 #include <string.h>
 
+static inline GQuark
+input_quark(void)
+{
+	return g_quark_from_static_string("input");
+}
+
 /**
  * Find the "input" configuration block for the specified plugin.
  *
@@ -32,16 +39,19 @@
  * @return the configuration block, or NULL if none was configured
  */
 static const struct config_param *
-input_plugin_config(const char *plugin_name)
+input_plugin_config(const char *plugin_name, GError **error_r)
 {
 	const struct config_param *param = NULL;
 
 	while ((param = config_get_next_param(CONF_INPUT, param)) != NULL) {
 		const char *name =
 			config_get_block_string(param, "plugin", NULL);
-		if (name == NULL)
+		if (name == NULL) {
-			g_error("input configuration without 'plugin' name in line %d",
+			g_set_error(error_r, input_quark(), 0,
+				    "input configuration without 'plugin' name in line %d",
 				    param->line);
+			return NULL;
+		}
 
 		if (strcmp(name, plugin_name) == 0)
 			return param;
@@ -50,22 +60,37 @@ input_plugin_config(const char *plugin_name)
 	return NULL;
 }
 
-void input_stream_global_init(void)
+bool
+input_stream_global_init(GError **error_r)
 {
+	GError *error = NULL;
+
 	for (unsigned i = 0; input_plugins[i] != NULL; ++i) {
 		const struct input_plugin *plugin = input_plugins[i];
 		const struct config_param *param =
-			input_plugin_config(plugin->name);
+			input_plugin_config(plugin->name, &error);
+		if (param == NULL && error != NULL) {
+			g_propagate_error(error_r, error);
+			return false;
+		}
 
 		if (!config_get_block_bool(param, "enabled", true))
 			/* the plugin is disabled in mpd.conf */
 			continue;
 
-		if (plugin->init == NULL || plugin->init(param))
+		if (plugin->init == NULL || plugin->init(param, &error))
 			input_plugins_enabled[i] = true;
+		else {
+			g_propagate_prefixed_error(error_r, error,
+						   "Failed to initialize input plugin '%s': ",
+						   plugin->name);
+			return false;
 		}
 	}
 
+	return true;
+}
+
 void input_stream_global_finish(void)
 {
 	for (unsigned i = 0; input_plugins[i] != NULL; ++i)

src/input_init.h

@@ -22,10 +22,17 @@
 
 #include "check.h"
 
+#include <glib.h>
+#include <stdbool.h>
+
 /**
  * Initializes this library and all input_stream implementations.
+ *
+ * @param error_r location to store the error occuring, or NULL to
+ * ignore errors
  */
-void input_stream_global_init(void);
+bool
+input_stream_global_init(GError **error_r);
 
 /**
  * Deinitializes this library and all input_stream implementations.

src/input_plugin.h

@@ -35,10 +35,12 @@ struct input_plugin {
 	/**
 	 * Global initialization.  This method is called when MPD starts.
 	 *
+	 * @param error_r location to store the error occuring, or
+	 * NULL to ignore errors
 	 * @return true on success, false if the plugin should be
 	 * disabled
 	 */
-	bool (*init)(const struct config_param *param);
+	bool (*init)(const struct config_param *param, GError **error_r);
 
 	/**
 	 * Global deinitialization.  Called once before MPD shuts

src/main.c

@@ -349,7 +349,13 @@ int main(int argc, char *argv[])
 	client_manager_init();
 	replay_gain_global_init();
 	initNormalization();
-	input_stream_global_init();
+
+	if (!input_stream_global_init(&error)) {
+		g_warning("%s", error->message);
+		g_error_free(error);
+		return EXIT_FAILURE;
+	}
+
 	playlist_list_global_init();
 
 	daemonize(options.daemon);

test/dump_playlist.c

@@ -74,7 +74,12 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	input_stream_global_init();
+	if (!input_stream_global_init(&error)) {
+		g_warning("%s", error->message);
+		g_error_free(error);
+		return 2;
+	}
+
 	playlist_list_global_init();
 
 	/* open the playlist */

test/read_tags.c

@@ -129,6 +129,7 @@ print_tag(const struct tag *tag)
 
 int main(int argc, char **argv)
 {
+	GError *error = NULL;
 	const char *decoder_name, *path;
 	const struct decoder_plugin *plugin;
 	struct tag *tag;
@@ -147,7 +148,12 @@ int main(int argc, char **argv)
 	decoder_name = argv[1];
 	path = argv[2];
 
-	input_stream_global_init();
+	if (!input_stream_global_init(&error)) {
+		g_warning("%s", error->message);
+		g_error_free(error);
+		return 2;
+	}
+
 	decoder_plugin_init_all();
 
 	plugin = decoder_plugin_from_name(decoder_name);

test/run_decoder.c

@@ -138,6 +138,7 @@ decoder_tag(G_GNUC_UNUSED struct decoder *decoder,
 
 int main(int argc, char **argv)
 {
+	GError *error = NULL;
 	bool ret;
 	const char *decoder_name;
 	struct decoder decoder;
@@ -152,7 +153,12 @@ int main(int argc, char **argv)
 
 	g_log_set_default_handler(my_log_func, NULL);
 
-	input_stream_global_init();
+	if (!input_stream_global_init(&error)) {
+		g_warning("%s", error->message);
+		g_error_free(error);
+		return 2;
+	}
+
 	decoder_plugin_init_all();
 
 	decoder.plugin = decoder_plugin_from_name(decoder_name);

test/run_input.c

@@ -41,6 +41,7 @@ my_log_func(const gchar *log_domain, G_GNUC_UNUSED GLogLevelFlags log_level,
 int main(int argc, char **argv)
 {
 	struct input_stream is;
+	GError *error = NULL;
 	bool success;
 	char buffer[4096];
 	size_t num_read;
@@ -60,7 +61,12 @@ int main(int argc, char **argv)
 
 	tag_pool_init();
 	config_global_init();
-	input_stream_global_init();
+
+	if (!input_stream_global_init(&error)) {
+		g_warning("%s", error->message);
+		g_error_free(error);
+		return 2;
+	}
 
 	/* open the stream and wait until it becomes ready */