Bug #17873 Error message for FORCE INDEX () with wrong parameter(s) is Incorrect

Description:
If you use FORCE INDEX () in a SELECT and give it a wrong parameter (i.e., a column name rather than an index name), it gives an error message of:

ERROR 1072 (42000): Key column 'a' doesn't exist in table

When in fact, 'a' does exist and it is a key column (as you can see fromthe following example).

How to repeat:
CREATE TABLE t1 ( a INT PRIMARY KEY );
SELECT * FROM t1 FORCE INDEX (a);

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/6936

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/7003

ChangeSet
  1.2490 06/05/30 00:08:58 igor@rurik.mysql.com +33 -0
  Fixed bug #17873: confusing error message when IGNORE/USE/FORCE INDEX
  refers to a column name.

Fix will appear in 4.1.21, 5.0.23, 5.1.11

Noted in 4.1.21, 5.0.23, 5.1.12 changelogs.

For a reference to a non-existent index in FORCE INDEX, the error
message referred to a column, not an index.