Bug#42675: Dangling pointer leads to a client crash (mysys/my_error.c \ 	patch enclosed)    One call to my_error_unregister_all() would free pointers, but leave one pointer to just-freed memory still assigned.  That's the bug.  Subsequent calls of this function would try to follow pointers into deallocated,  garbage memory and almost certainly SEGV.
Bug#42675: Dangling pointer leads to a client crash (mysys/my_error.c \
	patch enclosed)
  
One call to my_error_unregister_all() would free pointers, but leave one
pointer to just-freed memory still assigned.  That's the bug.  Subsequent
calls of this function would try to follow pointers into deallocated, 
garbage memory and almost certainly SEGV.

Now, after freeing a linked list, unset the initial pointer.

slanterns/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,ollie314/server,ollie314/server,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,ollie314/server,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2