Anyone knows for what this is used:

TreeListMorph>>
addSubmorphsAfter: parentMorph fromCollection: aCollection allowSorting: sortBoolean
������ "Update the font on each morph."
������
������ |answer|
������ answer := super addSubmorphsAfter: parentMorph fromCollection: aCollection allowSorting: sortBoolean.

"---- THIS TAKES TIME ----"

������ self scroller submorphsDo: [:i |
������ ������ i
������ ������ ������ font: self font;
������ ������ ������ extent: i minWidth @ i minHeight].
"---- XXXXX ----"

������ ^answer

setting the font and extent on all scroller submorphs is extremly
slow.
Try to merge a package with many changes, it takes up to several minutes until
the DiffMorph shows up.

Removing the above lines makes the DiffMorph much faster and I can not see
any visual difference.

nicolai