BUG#12659 error handling in federated needs improvement. Sanja pointed out that we were copying an entire buffer, most of which was probably garbage, and possibly hidden by null termination in the middle of the buffer. Now we are only copying the error message.


sql/ha_federated.cc:
  now recording only the error message, and not additional garbage. Storing the buffer length.
sql/ha_federated.h:
  added buffer length variable