Index: mysql-test/r/plugin_uninstall_audit_core.result
===================================================================
--- mysql-test/r/plugin_uninstall_audit_core.result	(版本 0)
+++ mysql-test/r/plugin_uninstall_audit_core.result	(版本 5999)
@@ -0,0 +1,10 @@
+INSTALL plugin NULL_AUDIT soname 'adt_null.so';
+SET DEBUG_SYNC= 'before_my_plugin_lock SIGNAL may_uninstall WAIT_FOR uninstall_plugin';
+SELECT 1+1;
+SET DEBUG_SYNC= 'in_mysql_uninstall_plugin WAIT_FOR may_uninstall';
+SET DEBUG_SYNC= 'after_plugin_is_deleted SIGNAL uninstall_plugin';
+UNINSTALL plugin NULL_AUDIT;
+Warnings:
+Warning	1620	Plugin is busy and will be uninstalled on shutdown
+1+1
+2
Index: mysql-test/t/plugin_uninstall_audit_core.test
===================================================================
--- mysql-test/t/plugin_uninstall_audit_core.test	(版本 0)
+++ mysql-test/t/plugin_uninstall_audit_core.test	(版本 5999)
@@ -0,0 +1,19 @@
+--source include/have_debug_sync.inc
+
+--connect (conn1, localhost, root, ,)
+--connect (conn2, localhost, root, ,)
+
+--connection conn1
+send INSTALL plugin NULL_AUDIT soname 'adt_null.so';
+reap;
+SET DEBUG_SYNC= 'before_my_plugin_lock SIGNAL may_uninstall WAIT_FOR uninstall_plugin';
+send SELECT 1+1;
+
+--connection conn2
+SET DEBUG_SYNC= 'in_mysql_uninstall_plugin WAIT_FOR may_uninstall'; 
+SET DEBUG_SYNC= 'after_plugin_is_deleted SIGNAL uninstall_plugin';
+send UNINSTALL plugin NULL_AUDIT;
+reap;
+
+--connection conn1
+reap;
Index: sql/sql_plugin.cc
===================================================================
--- sql/sql_plugin.cc	(版本 5792)
+++ sql/sql_plugin.cc	(工作副本)
@@ -33,6 +33,7 @@
 #include "sql_audit.h"
 #include <mysql/plugin_auth.h>
 #include "lock.h"                               // MYSQL_LOCK_IGNORE_TIMEOUT
+#include "debug_sync.h"
 #define REPORT_TO_LOG  1
 #define REPORT_TO_USER 2
 
@@ -1847,6 +1848,7 @@
 
 bool mysql_uninstall_plugin(THD *thd, const LEX_STRING *name)
 {
+  DEBUG_SYNC(thd, "in_mysql_uninstall_plugin");
   TABLE *table;
   TABLE_LIST tables;
   struct st_plugin_int *plugin;
@@ -1918,6 +1920,7 @@
   }
 
   plugin->state= PLUGIN_IS_DELETED;
+  DEBUG_SYNC(thd, "after_plugin_is_deleted");
   if (plugin->ref_count)
     push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                  WARN_PLUGIN_BUSY, ER(WARN_PLUGIN_BUSY));
Index: sql/sql_audit.cc
===================================================================
--- sql/sql_audit.cc	(版本 5792)
+++ sql/sql_audit.cc	(工作副本)
@@ -15,7 +15,7 @@
 
 #include "sql_priv.h"
 #include "sql_audit.h"
-
+#include "debug_sync.h"
 extern int initialize_audit_plugin(st_plugin_int *plugin);
 extern int finalize_audit_plugin(st_plugin_int *plugin);
 
@@ -160,8 +160,10 @@
   }
   
   /* lock the plugin and add it to the list */
+  DEBUG_SYNC(thd, "before_my_plugin_lock");
   plugin= my_plugin_lock(NULL, &plugin);
-  insert_dynamic(&thd->audit_class_plugins, (uchar*) &plugin);
+  if (plugin != NULL)
+    insert_dynamic(&thd->audit_class_plugins, (uchar*) &plugin);
 
   return 0;
 }