Print better error message if no plugins are available (fixes #284)

zathura/plugin.c

@@ -195,15 +195,16 @@ load_dir(void* data, void* userdata)
   }
 }
 
-void
+bool
 zathura_plugin_manager_load(zathura_plugin_manager_t* plugin_manager)
 {
   if (plugin_manager == NULL || plugin_manager->path == NULL) {
-    return;
+    return false;
   }
 
   /* read all files in the plugin directory */
   girara_list_foreach(plugin_manager->path, load_dir, plugin_manager);
+  return girara_list_size(plugin_manager->plugins) > 0;
 }
 
 zathura_plugin_t*

zathura/plugin.h

@@ -37,8 +37,9 @@ void zathura_plugin_manager_add_dir(zathura_plugin_manager_t* plugin_manager, co
  * Loads all plugins available in the previously given directories
  *
  * @param plugin_manager The plugin manager
+ * @return Success if some plugins have been loaded, false otherwise
  */
-void zathura_plugin_manager_load(zathura_plugin_manager_t* plugin_manager);
+bool zathura_plugin_manager_load(zathura_plugin_manager_t* plugin_manager);
 
 /**
  * Returns the (if available) associated plugin

zathura/zathura.c

@@ -430,7 +430,9 @@ zathura_init(zathura_t* zathura)
   g_set_prgname("org.pwmt.zathura");
 
   /* load plugins */
-  zathura_plugin_manager_load(zathura->plugins.manager);
+  if (zathura_plugin_manager_load(zathura->plugins.manager) == false) {
+    girara_error("Found no plugins. Please install at least one plugin.");
+  }
 
   /* configuration */
   config_load_default(zathura);