User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20021130 Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20021130 When you shift-click to select a list of items in a mulitple selection box on a form and the first item is no longer visible, in addition to highlighting the items, Mozilla re-orients the selection box to place the last item selected at the bottom of the box. This process works in reverse as well - if you shift-click an item above the first one selected, the multiple selection box is re-oriented upwards. Users, however, do not expect this change and may find it disorienting. Reproducible: Always Steps to Reproduce: Click on any item in the Product window. Scroll down until the highlighted item is completely out of view. Then shift-click an item in the middle of the multiple selection window and watch the window re-orient itself. Actual Results: The multiple selection window moved the contents inside, which I was not expecting. Expected Results: Mozilla should only have highlighted the items I selected. Adjusting the view of the multiple selection box as well makes it harder to confirm that one did select what one intended to select.

This is probably a result of bug 143815, in which ScrollFrameIntoView was fixed to handle nested scroll views.... I'm surprised that SCROLL_IF_NOT_VISIBLE is moving things that much, though...

Actually this has a simple explanation. Bug 34297 introduced code that scrolled the index into view whenever an option was selected. Thus a multiple selection scrolls all the intervening indices into view. Finally the clicked index is scrolled into view but by then the damage has been done.