diff --git a/include/mysql/plugin.h b/include/mysql/plugin.h
index 8490d59643b..77d141d5282 100644
--- a/include/mysql/plugin.h
+++ b/include/mysql/plugin.h
@@ -257,7 +257,7 @@ typedef void (*mysql_var_update_func)(MYSQL_THD thd,
 #define DECLARE_MYSQL_SYSVAR_BASIC(name, type) struct { \
   MYSQL_PLUGIN_VAR_HEADER;      \
   type *value;                  \
-  type def_val;                 \
+  const type def_val;                 \
 } MYSQL_SYSVAR_NAME(name)
 
 #define DECLARE_MYSQL_SYSVAR_SIMPLE(name, type) struct { \
@@ -279,7 +279,7 @@ typedef void (*mysql_var_update_func)(MYSQL_THD thd,
 #define DECLARE_MYSQL_THDVAR_BASIC(name, type) struct { \
   MYSQL_PLUGIN_VAR_HEADER;      \
   int offset;                   \
-  type def_val;                 \
+  const type def_val;           \
   DECLARE_THDVAR_FUNC(type);    \
 } MYSQL_SYSVAR_NAME(name)
 
@@ -294,7 +294,7 @@ typedef void (*mysql_var_update_func)(MYSQL_THD thd,
 #define DECLARE_MYSQL_THDVAR_TYPELIB(name, type) struct { \
   MYSQL_PLUGIN_VAR_HEADER;      \
   int offset;                   \
-  type def_val;                 \
+  const type def_val;           \
   DECLARE_THDVAR_FUNC(type);    \
   TYPELIB *typelib;             \
 } MYSQL_SYSVAR_NAME(name)
diff --git a/storage/maria/ma_init.c b/storage/maria/ma_init.c
index 838e9814c89..d0eea52e341 100644
--- a/storage/maria/ma_init.c
+++ b/storage/maria/ma_init.c
@@ -22,6 +22,9 @@
 #include "ma_checkpoint.h"
 #include <hash.h>
 
+static my_bool maria_upgrade();
+
+
 void history_state_free(MARIA_STATE_HISTORY_CLOSED *closed_history)
 {
   MARIA_STATE_HISTORY *history, *next;
@@ -65,6 +68,8 @@ int maria_init(void)
               maria_block_size % MARIA_MIN_KEY_BLOCK_LENGTH == 0);
   if (!maria_inited)
   {
+    if (maria_upgrade())
+      return 1;
     maria_inited= TRUE;
     pthread_mutex_init(&THR_LOCK_maria,MY_MUTEX_INIT_SLOW);
     _ma_init_block_record_data();
@@ -113,3 +118,72 @@ void maria_end(void)
     hash_free(&maria_stored_state);
   }
 }
+
+/**
+   Upgrade from older Aria versions:
+
+  - In MariaDB 5.1, the name of the control file and log files had the
+    'maria' prefix, now they have the 'aria' prefix.
+
+  @return: 0 ok
+           1 error
+
+*/
+
+static my_bool maria_upgrade()
+{
+  char name[FN_REFLEN], new_name[FN_REFLEN];
+  DBUG_ENTER("maria_upgrade");
+
+  fn_format(name, "maria_log_control", maria_data_root, "", MYF(MY_WME));
+
+  if (!my_access(name,F_OK))
+  {
+    /*
+      Old style control file found; Rename the control file and the log files.
+      We start by renaming all log files, so that if we get a crash
+      we will continue from where we left.
+    */
+    uint i;
+    MY_DIR *dir= my_dir(maria_data_root, MYF(MY_WME));
+    if (!dir)
+      DBUG_RETURN(1);
+
+    my_message(HA_ERR_INITIALIZATION,
+               "Found old style Maria log files; "
+               "Converting them to Aria names",
+               MYF(ME_JUST_INFO));
+
+    for (i= 0; i < dir->number_off_files; i++)
+    {
+      const char *file= dir->dir_entry[i].name;
+      if (strncmp(file, "maria_log.", 10) == 0 &&
+          file[10] >= '0' && file[10] <= '9' &&
+        file[11] >= '0' && file[11] <= '9' &&
+        file[12] >= '0' && file[12] <= '9' &&
+        file[13] >= '0' && file[13] <= '9' &&
+        file[14] >= '0' && file[14] <= '9' &&
+        file[15] >= '0' && file[15] <= '9' &&
+        file[16] >= '0' && file[16] <= '9' &&
+        file[17] >= '0' && file[17] <= '9' &&
+        file[18] == '\0')
+      {
+        /* Remove the 'm' in 'maria' */
+        char old_logname[FN_REFLEN], new_logname[FN_REFLEN];
+        fn_format(old_logname, file, maria_data_root, "", MYF(0));
+        fn_format(new_logname, file+1, maria_data_root, "", MYF(0));
+        if (my_rename(old_logname, new_logname, MYF(MY_WME)))
+        {
+          my_dirend(dir);
+          DBUG_RETURN(1);
+        }
+      }
+    }
+    my_dirend(dir);
+    
+    fn_format(new_name, CONTROL_FILE_BASE_NAME, maria_data_root, "", MYF(0));
+    if (my_rename(name, new_name, MYF(MY_WME)))
+      DBUG_RETURN(1);
+  }
+  DBUG_RETURN(0);
+}
diff --git a/storage/maria/unittest/ma_maria_log_cleanup.c b/storage/maria/unittest/ma_maria_log_cleanup.c
index 6eeb0c6856a..f85c75b1a88 100644
--- a/storage/maria/unittest/ma_maria_log_cleanup.c
+++ b/storage/maria/unittest/ma_maria_log_cleanup.c
@@ -38,7 +38,8 @@ my_bool maria_log_remove()
   for (i= 0; i < dirp->number_off_files; i++)
   {
     char *file= dirp->dir_entry[i].name;
-    if (strncmp(file, "aria_log.", 10) == 0 &&
+    if (strncmp(file, "aria_log.", 9) == 0 &&
+        file[9] >= '0' && file[9] <= '9' &&
         file[10] >= '0' && file[10] <= '9' &&
         file[11] >= '0' && file[11] <= '9' &&
         file[12] >= '0' && file[12] <= '9' &&
@@ -46,8 +47,7 @@ my_bool maria_log_remove()
         file[14] >= '0' && file[14] <= '9' &&
         file[15] >= '0' && file[15] <= '9' &&
         file[16] >= '0' && file[16] <= '9' &&
-        file[17] >= '0' && file[17] <= '9' &&
-        file[18] == '\0')
+        file[17] == '\0')
     {
       if (fn_format(file_name, file,
                     maria_data_root, "", MYF(MY_WME)) == NullS ||