tree f35f055b6fec1c4d0702a6697203fd8de883a79b
parent 30a8239ffc874ec6c895ff220c6625277c530add
author commit-queue@webkit.org <commit-queue@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1412230259 +0000
committer commit-queue@webkit.org <commit-queue@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1412230259 +0000

Click events offset in webkit-overflow-scrolling iframes
https://bugs.webkit.org/show_bug.cgi?id=134596

Patch by Benjamin Poulain <bpoulain@apple.com> on 2014-10-01
Reviewed by Sam Weinig.

* platform/ScrollView.cpp:
(WebCore::ScrollView::visibleContentRectInternal):
When converting coordinates from the main frame to a subframe's document, the position
is first converted to the subframe's FrameView coordinate system, then offset by the scroll
offset of the subframe itself.

The bug in this case was that the scroll offset used was the global scroll offset of the frame
in the view instead of the scroll offset of the document in its own frameview.

The regression was introduced by the refactoring r162663. On iOS WebKit1, the coordinate system
is different depending on VisibleContentRectIncludesScrollbars. In r162663, the value was set
such that the rect returned is always in absolute coordinate.

The ideal solution would be to refactor ScrollView::platformVisibleContentRect() to always return
the offsets in scroll view coordinates and verify and update all the call sites to use explicit
conversion to the top frame. In this patch I only reverted the coordinate change of r162663 to avoid
large scale impact.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@174199 268f45cc-cd09-0410-ab3c-d52691b4dbfc