Problem:

The problem is that explain_filename-t is not printing a test plan as
required by the TAP protocol. The test invokes plan(NO_PLAN) but does not
invoke exit_status() at the end, where the plan would be printed.

Solution:

Invoke exit_status() at the end.

Backport to 5.5
(external Bug#69407 Build warnings with mysql)


support-files/build-tags:
  Run etags on sql_yacc.yy, ignore other .yy files
unittest/mysys/explain_filename-t.cc:
  NO_PLAN seems to fail on some platforms, use the actual number instead.

SHOW ENGINE INNOD

Problem:

The purpose of explain_filename() is to provide useful additional
information regarding the partitions given the filename.  This function
was returning an error when it was not able to parse the given filename.
For example, within InnoDB, temporary files are created with #sql-
prefix.  But this function was not able to parse it correctly.

Solution:

It is not an error, if explain_filename() could not parse the given
filename.  If there is no partition information to explain, then silently
return from the function.

rb#1940 approved by mattiasj