src/plugin.c: Move the error-checking code up.

This way the error message is much closer to the check and we save one
level of indentation for the "good" code.

diff --git a/src/plugin.c b/src/plugin.c
index 52a5ea0..eb98a7a 100644 (file)
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -1,6 +1,6 @@
 /**
  * collectd - src/plugin.c
- * Copyright (C) 2005-2010  Florian octo Forster
+ * Copyright (C) 2005-2011  Florian octo Forster
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -729,35 +729,36 @@ static int plugin_insert_read (read_func_t *rf)
        }
 
        le = llist_search (read_list, rf->rf_name);
-       if (le == NULL)
+       if (le != NULL)
        {
-               le = llentry_create (rf->rf_name, rf);
-               if (le == NULL)
-               {
-                       pthread_mutex_unlock (&read_lock);
-                       ERROR ("plugin_insert_read: llentry_create failed.");
-                       return (-1);
-               }
-
-               status = c_heap_insert (read_heap, rf);
-               if (status != 0)
-               {
-                       pthread_mutex_unlock (&read_lock);
-                       ERROR ("plugin_insert_read: c_heap_insert failed.");
-                       llentry_destroy (le);
-                       return (-1);
-               }
+               pthread_mutex_unlock (&read_lock);
+               WARNING ("The read function \"%s\" is already registered. "
+                               "Check for duplicate \"LoadPlugin\" lines "
+                               "in your configuration!",
+                               rf->rf_name);
+               return (EINVAL);
+       }
 
-               /* This does not fail. */
-               llist_append (read_list, le);
+       le = llentry_create (rf->rf_name, rf);
+       if (le == NULL)
+       {
+               pthread_mutex_unlock (&read_lock);
+               ERROR ("plugin_insert_read: llentry_create failed.");
+               return (-1);
        }
-       else
+
+       status = c_heap_insert (read_heap, rf);
+       if (status != 0)
        {
-               INFO ("plugin: plugin_insert_read: "
-                               "read function for plugin `%s' already added.",
-                               rf->rf_name);
+               pthread_mutex_unlock (&read_lock);
+               ERROR ("plugin_insert_read: c_heap_insert failed.");
+               llentry_destroy (le);
+               return (-1);
        }
 
+       /* This does not fail. */
+       llist_append (read_list, le);
+
        pthread_mutex_unlock (&read_lock);
        return (0);
 } /* int plugin_insert_read */