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Description
Migrated from rt.cpan.org#119079 (status was 'open')
Requestors:
From tzs@eacceleration.com on 2016-11-30 20:18:37:
At line 1884 of dbdimp.c, it handles the mysql_enable_utf8/mysql_enable_utf8mb4 flags in the options hash:
if ((svp = hv_fetch(hv, "mysql_enable_utf8mb4", 20, FALSE)) && *svp && SvTRUE(*svp)) {
mysql_options(sock, MYSQL_SET_CHARSET_NAME, "utf8mb4");
}
else if ((svp = hv_fetch(hv, "mysql_enable_utf8", 17, FALSE)) && *svp) {
/* Do not touch imp_dbh->enable_utf8 as we are called earlier
* than it is set and mysql_options() must be before:
* mysql_real_connect()
*/
mysql_options(sock, MYSQL_SET_CHARSET_NAME,
(SvTRUE(*svp) ? "utf8" : "latin1"));
if (DBIc_TRACE_LEVEL(imp_xxh) >= 2)
PerlIO_printf(DBIc_LOGPIO(imp_xxh),
"mysql_options: MYSQL_SET_CHARSET_NAME=%s\n",
(SvTRUE(*svp) ? "utf8" : "latin1"));
}
The logic here leads to surprising results. If when connecting you give this:
mysql_enable_utf8mb4 => 1
you get MYSQL_SET_CHARSET_NAME set to utf8mb4, as you would expect, . Similarly,
mysql_enable_utf8 => 1
gives MYSQL_SET_CHARSET_NAME set to utf8, just as expected, and not specifying either option results in MYSQL_SET_CHARSET_NAME not being set so you presumably get whatever the underlying mysql default is.
Where it gets weird is if you give one of these:
mysql_enable_utf8mb4 => 0
or
mysql_enable_utf8 => 0.
The former is equivalent to not specifying an option, and so you get the underlying mysql default for MYSQL_SET_CHARSET_NAME.
The later, however, results in MYSQL_SET_CHARSET_NAME set to latin1.
It seems quite counterintuitive that if I want latin1, the way to get it is with mysql_enable_utf8 => 0, and mysql_enable_utf8mb4 => 0 will not get that (unless that happens to be the underlying default).
--
Tim Smith
tzs@eacceleration.com
From michielb@cpan.org on 2016-12-01 08:12:50:
Hi Tim!
On Wed 30 Nov 2016 15:18:37, tzs@eacceleration.com wrote:
> It seems quite counterintuitive that if I want latin1, the way to get
> it is with mysql_enable_utf8 => 0, and mysql_enable_utf8mb4 => 0 will
> not get that (unless that happens to be the underlying default).
You're right on that! Also, the behaviour of mysql_enable_utf8 => 0 is not documented.
My proposal would be to explicitly document this behavior and leave it at that. Do you agree?
--
Michiel
From pali@cpan.org on 2017-03-01 13:26:03: