Cleanup of unused variables.

Fixed "discover" in the handler API.

Fixed problem where handlerton was not zero'ed. I need to look around, I suspect this problem is more widespread. 


sql/ha_innodb.h:
  Unused variable
sql/ha_ndbcluster.cc:
  Added "discover" to handlerton.
sql/handler.cc:
  Added plugin loop and correctly now use handler API.
sql/handler.h:
  Removed unused variable. Added discover to handler API
sql/mysqld.cc:
  Removed unused variables.
sql/sql_plugin.cc:
  Fixed DBUG Enter comment (obvious cut paste mistake)
storage/csv/ha_tina.cc:
  Found that if we don't bzero handlerton, that things can go boom!
  
  This probably needs to be fixed for all handlers

sql/ha_innodb.h

@@ -227,12 +227,6 @@ extern my_bool innobase_log_archive,
 	innobase_use_native_aio,
 	innobase_file_per_table, innobase_locks_unsafe_for_binlog,
 	innobase_create_status_file;
-extern my_bool innobase_very_fast_shutdown;	/* set this to 1 just before
-						calling innobase_end() if
-						you want InnoDB to shut down
-						without flushing the buffer
-						pool: this is equivalent to
-						a 'crash' */
 extern "C" {
 extern ulong srv_max_buf_pool_modified_pct;
 extern ulong srv_max_purge_lag;

sql/ha_ndbcluster.cc

@@ -6387,6 +6387,7 @@ static int ndbcluster_init()
     ndbcluster_binlog_init_handlerton();
 #endif
     h.flags=            HTON_CAN_RECREATE | HTON_TEMPORARY_NOT_SUPPORTED;
+    h.discover=         ndbcluster_discover;
   }
 
   if (have_ndbcluster != SHOW_OPTION_YES)

sql/handler.cc

@@ -2705,18 +2705,41 @@ int ha_change_key_cache(KEY_CACHE *old_key_cache,
     >0 : error.  frmblob and frmlen may not be set
 */
 
+typedef struct st_discover_args
+{
+  const char *db;
+  const char *name;
+  const void** frmblob; 
+  uint* frmlen;
+};
+
+static my_bool discover_handlerton(THD *thd, st_plugin_int *plugin,
+                                   void *arg)
+{
+  st_discover_args *vargs= (st_discover_args *)arg;
+  handlerton *hton= (handlerton *)plugin->data;
+  if (hton->state == SHOW_OPTION_YES && hton->discover &&
+      (!(hton->discover(thd, vargs->db, vargs->name, vargs->frmblob, vargs->frmlen))))
+    return TRUE;
+
+  return FALSE;
+}
+
 int ha_discover(THD *thd, const char *db, const char *name,
 		const void **frmblob, uint *frmlen)
 {
   int error= -1; // Table does not exist in any handler
   DBUG_ENTER("ha_discover");
   DBUG_PRINT("enter", ("db: %s, name: %s", db, name));
+  st_discover_args args= {db, name, frmblob, frmlen};
+
   if (is_prefix(name,tmp_file_prefix)) /* skip temporary tables */
     DBUG_RETURN(error);
-#ifdef WITH_NDBCLUSTER_STORAGE_ENGINE
-  if (have_ndbcluster == SHOW_OPTION_YES)
-    error= ndbcluster_discover(thd, db, name, frmblob, frmlen);
-#endif
+
+  if (plugin_foreach(thd, discover_handlerton,
+                 MYSQL_STORAGE_ENGINE_PLUGIN, &args))
+    error= 0;
+
   if (!error)
     statistic_increment(thd->status_var.ha_discover_count,&LOCK_status);
   DBUG_RETURN(error);

sql/handler.h

@@ -667,6 +667,8 @@ struct handlerton
    enum handler_create_iterator_result
      (*create_iterator)(enum handler_iterator_type type,
                         struct handler_iterator *fill_this_in);
+   int (*discover)(THD* thd, const char *db, const char *name,
+                           const void** frmblob, uint* frmlen);
 };
 
 
@@ -1589,7 +1591,6 @@ private:
 
 	/* Some extern variables used with handlers */
 
-extern handlerton *sys_table_types[];
 extern const char *ha_row_type[];
 extern TYPELIB tx_isolation_typelib;
 extern TYPELIB myisam_stats_method_typelib;

sql/mysqld.cc

@@ -357,9 +357,7 @@ my_bool opt_show_slave_auth_info, opt_sql_bin_update = 0;
 my_bool opt_log_slave_updates= 0;
 my_bool	opt_innodb;
 #ifdef WITH_INNOBASE_STORAGE_ENGINE
-extern uint innobase_init_flags, innobase_lock_type;
-extern uint innobase_flush_log_at_trx_commit;
-extern ulong innobase_cache_size, innobase_fast_shutdown;
+extern ulong innobase_fast_shutdown;
 extern ulong innobase_large_page_size;
 extern char *innobase_home, *innobase_tmpdir, *innobase_logdir;
 extern long innobase_lock_scan_time;
@@ -383,11 +381,6 @@ extern my_bool innobase_log_archive,
                innobase_use_native_aio,
                innobase_file_per_table, innobase_locks_unsafe_for_binlog,
                innobase_create_status_file;
-extern my_bool innobase_very_fast_shutdown; /* set this to 1 just before
-                                            calling innobase_end() if you want
-                                            InnoDB to shut down without
-                                            flushing the buffer pool: this
-                                            is equivalent to a 'crash' */
 extern "C" {
 extern ulong srv_max_buf_pool_modified_pct;
 extern ulong srv_max_purge_lag;

sql/sql_plugin.cc

@@ -927,7 +927,7 @@ my_bool plugin_foreach(THD *thd, plugin_foreach_func *func,
 {
   uint idx;
   struct st_plugin_int *plugin;
-  DBUG_ENTER("mysql_uninstall_plugin");
+  DBUG_ENTER("plugin_foreach");
   rw_rdlock(&THR_LOCK_plugin);
 
   if (type == MYSQL_ANY_PLUGIN)

storage/csv/ha_tina.cc

@@ -157,6 +157,7 @@ static int tina_init_func()
     VOID(pthread_mutex_init(&tina_mutex,MY_MUTEX_INIT_FAST));
     (void) hash_init(&tina_open_tables,system_charset_info,32,0,0,
                      (hash_get_key) tina_get_key,0,0);
+    bzero(&tina_hton, sizeof(handlerton));
     tina_hton.state= SHOW_OPTION_YES;
     tina_hton.db_type= DB_TYPE_CSV_DB;
     tina_hton.create= tina_create_handler;