When backing up a database with MYSQL_TYPE_GEOMETRY fields, mysqldump will output those fields in binary format by default. This causes issues upon restore.
The typical error returned by mysql when restoring such a dump is :
"Cannot get GEOMETRY object from the data you send to the Geometry field".
Using the --hex-blob option fails to treat GEOMETRY types as blobs.
A simple solution is to change the following line in mysqldump.c
field->type == MYSQL_TYPE_TINY_BLOB)) ? 1 : 0;
field->type == MYSQL_TYPE_TINY_BLOB ||
field->type == MYSQL_TYPE_GEOMETRY)) ? 1 : 0;
Debian Linux (Wheezy)