The original intention, as I saw it, was to encourage people from choosing 'MediaWiki' as the name of their wiki. Just hardcode it, I don't think we're changing the name anytime soon.
$this->startForm();
- if ( $this->getVar( 'wgSitename' ) == $GLOBALS['wgSitename'] ) {
+ // Encourage people to not name their site 'MediaWiki' by blanking the
+ // field. I think that was the intent with the original $GLOBALS['wgSitename']
+ // but these two always were the same so had the effect of making the
+ // installer forget $wgSitename when navigating back to this page.
+ if ( $this->getVar( 'wgSitename' ) == 'MediaWiki' ) {
$this->setVar( 'wgSitename', '' );
}