I was trying to upgrade from 1.16.5 to 1.18.0 on MySQL 5.5.16 using the web installer, but the script stopped on creating table iwlinks cos it used "DEFAULT CHARSET=mysql4". Creating iwlinks manually using "DEFAULT CHARSET=binary" fixed it and I could continue with the web installer.

...
...rev_len column already populated.
Creating iwlinks table...
An error occured:

A database query syntax error has occurred.
The last attempted database query was:
"CREATE TABLE iwlinks (
iwl_from int unsigned NOT NULL default 0,
iwl_prefix varbinary(20) NOT NULL default '',
iwl_title varchar(255) binary NOT NULL default ''
) ENGINE=InnoDB, DEFAULT CHARSET=mysql4
"
from within function "DatabaseBase::sourceFile( C:\xampp\htdocs\db18/maintenance/archives/patch-iwlinks.sql )".
Database returned error "1115: Unknown character set: 'mysql4' (localhost)"
Backtrace:
#0 C:\xampp\htdocs\db18\includes\db\Database.php(814): DatabaseBase->reportQueryError('Unknown charact...', 1115, 'CREATE TABLE `i...', 'DatabaseBase::s...', false)
#1 C:\xampp\htdocs\db18\includes\db\Database.php(3013): DatabaseBase->query('CREATE TABLE `i...', 'DatabaseBase::s...')
#2 C:\xampp\htdocs\db18\includes\db\Database.php(2911): DatabaseBase->sourceStream(Resource id #253, false, false, 'DatabaseBase::s...')
#3 C:\xampp\htdocs\db18\includes\installer\DatabaseUpdater.php(364): DatabaseBase->sourceFile('C:\xampp\htdocs...')
#4 C:\xampp\htdocs\db18\includes\installer\DatabaseUpdater.php(379): DatabaseUpdater->applyPatch('patch-iwlinks.s...', false)
#5 [internal function]: DatabaseUpdater->addTable('iwlinks', 'patch-iwlinks.s...')
#6 C:\xampp\htdocs\db18\includes\installer\DatabaseUpdater.php(233): call_user_func_array(Array, Array)
#7 C:\xampp\htdocs\db18\includes\installer\DatabaseUpdater.php(197): DatabaseUpdater->runUpdates(Array, false)
#8 C:\xampp\htdocs\db18\includes\installer\DatabaseInstaller.php(248): DatabaseUpdater->doUpdates()
#9 C:\xampp\htdocs\db18\includes\installer\WebInstallerPage.php(513): DatabaseInstaller->doUpgrade()
#10 C:\xampp\htdocs\db18\includes\installer\WebInstaller.php(254): WebInstaller_Upgrade->execute()
#11 C:\xampp\htdocs\db18\mw-config\index.php(50): WebInstaller->execute(Array)
#12 C:\xampp\htdocs\db18\mw-config\index.php(18): wfInstallerMain()
#13 {main}

Version: 1.18.x
Severity: normal