MySQL Bugs: #46310: mysql not handling <BACKSPACE> properly with multi-byte chars

Bug #46310	mysql not handling <BACKSPACE> properly with multi-byte chars
Submitted:	20 Jul 17:24	Modified:	25 Nov 15:51
Reporter:	Matthew Lord
Status:	Closed
Category:	Client	Severity:	S3 (Non-critical)
Version:	5.1.37, 5.0.84	OS:	Any
Assigned to:	Jim Winstead	Target Version:	5.1+
Tags:	backspace, MySQL, mult-byte char
Triage:	Triaged: D3 (Medium)

Description:
Using a UTF8 enabled terminal:

mysql test

mysql> set names utf8;

mysql> show tab°<BACKSPACE>les;

mysql> <UP ARROW>

How to repeat:
Using a UTF8 enabled terminal:

mysql test

mysql> set names utf8;

mysql> show tab°<BACKSPACE>les;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use near 'tab�les' at
line 1

mysql> show tab�les;

Suggested fix:
It looks like <BACKSPACE> is not multi-byte character aware.  Can we change this?  It
appears to work fine with readline so we should be able to do it
as well.

There are two problems here: libedit doesn't support multi-byte character sets, so it will
be broken as long as it is not supported there. For readline, we aren't testing for all
the necessary functions for multi-byte support, so it doesn't even try to deal with them.
We can fix it for readline, but not libedit.

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/79837

3054 Jim Winstead	2009-07-31
      Not all of the necessary tests for multi-byte support in readline
      were included in the configure tests. (Bug #46310)

Queued to 5.1-bugteam, will be merged up to mysql-pe.

See similar bug #47201

Pushed into 5.4.4-alpha (revid:alik@sun.com-20090914155317-m1g9wodmndzdj4l1) (version
source revid:alik@sun.com-20090914155317-m1g9wodmndzdj4l1) (merge vers: 5.4.4-alpha)
(pib:11)

The configure tests were updated to properly detect multi-byte support on the operating
system, which will allow  backspace to function properly in multi-byte environments.

This only fixes the behavior with readline -- libedit simply doesn't support multi-byte
character sets properly.

Noted in 5.4.4 changelog.

mysql did not handle backspace properly for multi-byte characters.
This has been fixed now if mysql is linked with the readline library.
It is not fixed if mysql is linked with libedit, which does not
contain the necessary support for multi-byte character sets.

Setting report to NDI pending push into 5.1.x.

Pushed into 5.1.39-ndb-6.3.28 (revid:jonas@mysql.com-20091001055605-ap2kiaarr7p40mmv)
(version source revid:jonas@mysql.com-20091001055605-ap2kiaarr7p40mmv) (merge vers:
5.1.39-ndb-6.3.28) (pib:11)

Pushed into 5.1.39-ndb-7.0.9 (revid:jonas@mysql.com-20091001072547-kv17uu06hfjhgjay)
(version source revid:jonas@mysql.com-20091001071652-irejtnumzbpsbgk2) (merge vers:
5.1.39-ndb-7.0.9) (pib:11)

Pushed into 5.1.39-ndb-7.1.0 (revid:jonas@mysql.com-20091001123013-g9ob2tsyctpw6zs0)
(version source revid:jonas@mysql.com-20091001123013-g9ob2tsyctpw6zs0) (merge vers:
5.1.39-ndb-7.1.0) (pib:11)

Pushed into 5.1.39-ndb-6.2.19 (revid:jonas@mysql.com-20091005103850-dwij2dojwpvf5hi6)
(version source revid:jonas@mysql.com-20090930185117-bhud4ek1y0hsj1nv) (merge vers:
5.1.39-ndb-6.2.19) (pib:11)

Setting report to NDI pending push into 5.1.x.

The 5.4 fix has been pushed to 5.4.2.

This patch did make it into the 5.1 tree in either the 5.1.38 or 5.1.39 timeframe. An
inspection of config/ac-macros/readline.m4 should make it obvious, look for
"AC_CHECK_FUNC(wctype".

Thanks for the hint. It appeared in 5.1.38.

Noted in 5.1.38 changelog.