Wikimedia Bugzilla is closed!

After updating an older mediawiki install to 1.23.3, the font-size of the site was too big. It completely changed the character of the site. This was surprising as update of a second install to 1.23.3 had no font-size problems. 

After grepping through the /skins/vector files the problem was found. The update to 1.23.3 the site that retained the proper font-size contained vector files dated Jan 27 2014, while the site where the font rendered too big had the same files dated Aug 27 2014. This made no sense because both sites were update by:

cd /srv/http/htdocs
mv mediawiki mediawiki-old
tar -xzf ~/tmp/mediawiki-1.23.3.tar.gz
ln -s mediawiki-1.23.3 mediawiki
cp -a mediawiki-old/LocalSettings.php mediawiki
cp -a mediawiki-old/skins/common/images/510* mediawiki/skins/common/images
read/verify RELEASE-NOTES-1.23
<done>

No skin files related to the vector skin were copied from old -> new. However, the Vector.php and skins/vector/* files ended up with two completely different file dates (as shown above). The specific file controlling vector font-size and causing the problem was variables.less.

The old/correct Jan 27 vector/variables.less file contained the following:

 @content-font-size: 0.8em;
 @content-line-height: 1.5em;
 @content-padding: 1.5em 1.5em 1.5em 1.75em;
 @content-heading-font-size: 1.6em;

The Aug 27 vector/variables.less file contained:

 @content-font-size: 0.875em;
 @content-line-height: 1.6;
 @content-padding: 1em;
 @content-heading-font-size: 1.8em;

I don't know how the updates ended up with two different versions of the vector skin, but it sure screwed up the look of the site. However this occurred, it shouldn't have and this should be clearly noted in the RELEASE-NOTES and the change corrected.