MDEV-11510 Audit plugin sometimes causes server to crash when using with MySQL.

Alexey Botchkov · Alexey Botchkov · commit 211cf9321a91 · 2016-12-16T18:37:11.000+04:00
MySQL has a bug failing to handle
           MYSQL_THDVAR_STR(...  PLUGIN_VAR_NOSYSVAR |
                                 PLUGIN_VAR_NOCMDOPT | PLUGIN_VAR_MEMALLOC)
        so fall back to just PLUGIN_VAR_READONLY | PLUGIN_VAR_MEMALLOC
        whem MySQL started.
diff --git a/plugin/server_audit/server_audit.c b/plugin/server_audit/server_audit.c
@@ -2845,6 +2845,7 @@ void __attribute__ ((constructor)) audit_plugin_so_init(void)
       _mysql_plugin_declarations_[0].info= mysql_v4_descriptor;
       use_event_data_for_disconnect= 1;
     }
+    MYSQL_SYSVAR_NAME(loc_info).flags= PLUGIN_VAR_READONLY | PLUGIN_VAR_MEMALLOC;
   }
 
   memset(locinfo_ini_value, 'O', sizeof(locinfo_ini_value)-1);

Original file line number	Diff line number	Diff line change
`@@ -2845,6 +2845,7 @@ void __attribute__ ((constructor)) audit_plugin_so_init(void)`
`2845`	`2845`	`_mysql_plugin_declarations_[0].info= mysql_v4_descriptor;`
`2846`	`2846`	`use_event_data_for_disconnect= 1;`
`2847`	`2847`	`}`
	`2848`	`+ MYSQL_SYSVAR_NAME(loc_info).flags= PLUGIN_VAR_READONLY \| PLUGIN_VAR_MEMALLOC;`
`2848`	`2849`	`}`
`2849`	`2850`
`2850`	`2851`	`memset(locinfo_ini_value, 'O', sizeof(locinfo_ini_value)-1);`