205725 - Scrollbars don't appear when replacing document element

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Peter Van der Beken [:peterv]]

I have a testcase where I'm adding text to a document and then remove and re-add
the documentElement, all in the onload handler. If I don't remove and re-add the
document element, the scrollbars appear correctly if the content doesn't fit in
the window, if I do remove and re-add they don't appear. While trying to make a
better testcase I noticed that it seems to be important that the document
doesn't need scrollbars before the onload handler runs and adds the content and
that the replacing of the documentElement needs to happen in the onload handler too.

Comment 1

[Peter Van der Beken [:peterv]]

Attachment: Testcase (no scrollbars)

Comment 2

[Peter Van der Beken [:peterv]]

Attachment: Testcase (scrollbars)

Comment 3

[Peter Van der Beken [:peterv]]

Attachment: Testcase (no scrollbars)

Comment 4

[Peter Van der Beken [:peterv]]

Attachment: Testcase (scrollbars)

Comment 5

[Johnny Stenback (:jst)]

This is the same old problem that we've hacked around before:

http://lxr.mozilla.org/seamonkey/source/content/html/document/src/nsHTMLDocument.cpp#2436

Comment 6

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

It wouldn't surprise me if this is the result of someone mindlessly
null-checking the result of GetParent rather than thinking about what to do if
it's null.  I've seen it happen before...

Comment 7

[Boris Zbarsky [:bzbarsky]]

So... this worksforme on trunk, for whatever reason.

No idea how to write a test for this, though.