[WebPositive] scollbar rendering bug on certain BeBook pages

[ribbonz]

open WebPositive
from the Bookmarks, load the BeBook (Documentation/BeBook)
click on 'Legal Notices'

resize the browser window to make it wider
the "pointer" arrows at the top and bottom of the vertical scrollbar on the right disappear
or actually, it's as if the background of the current page is rendered over them

many other pages in the BeBook display this anomaly
some don't -- e.g. the 'Introduction' page never renders the scrollbars incorrectly

my system is using the default Vesa graphics driver
gcc4

Web+ revision: 577
Haiku version: hrev41667

[ribbonz]

update:

after looking at some more pages from the BeBook, it appears that the problem may stem from displaying a vertical scrollbar when it's not necessary.

The 'Introduction' page that never renders incorrectly is also long enough (i.e. contains enough lines) that a scrollbar to move up and down the page is needed. But the 'Legal Notice' page, along with the other problem pages, is small enough to easily fit in the window, and no scrolling up or down is required.

so maybe the actual bug is the renderer not correctly figuring out (in some cases) that a vertical scrollbar isn't needed.

[ribbonz]

update 2:

investigated some more...

made a copy of the 'Legal Notice' page and put into /boot/home
no scrollbar problem when this is displayed... but the stylesheet info is missing

copied over the 'be_book.css' and 'be_book_ie.css' files into /boot/home as well...
the scrollbar rendering problem has returned

scanned through 'be_book.css' and found this suspicious looking entry at the top:

html {

overflow-y: scroll;

}

removed that one line so that the 'html' entry was blank, i.e.

html { }

re-loaded the local copy, and... voila... the scrollbar display bug is gone
no vertical scrollbar is rendered unless the browser window is made very short in height (i.e. the scrollbar only shows up when necessary -- the way it should be)

so, apparently, WebPositive does not like the "overflow-y: scroll;" stylesheet designation too much

[mmadia]

R1 Alpha 3 has not yet been released. This was with an R1 Alpha 3 Release Candidate image.

[leavengood]

I would need to investigate, but I suspect we just don't render disabled scrollbars correctly in our WebKit port. Even though they look like Haiku scrollbars (mainly thanks to stippi), they are rendered by WebKit. In the case of this CSS, the correct behavior is to show a disabled scrollbar. When I get a chance I'll open the BeBook in browser on another OS to see how it looks.

I have other scrollbar fixes to make, but I'm still working on updating our WebKit so I may not get to this for a while.

[mmadia]

Hi. Our WebKit port (and thus WebPositive) was updated in July. Could you retest this in a new nightly image and report back? ​http://www.haiku-files.org/haiku/development Thanks!

[leavengood]

I tested again and it is still there. Looking at the same page in Firefox the scrollbar is there but disabled. So as I suspected last year I think this is just our scrollbar rendering not properly handling disabled scrollbars on a web page.

I still haven't gotten set up working on the new WebKit, so unless Alexandre looks at this and fixes it soon himself, it probably won't get fixed for a while. While ugly, it isn't a critical bug.

[pulkomandy]

Still visible in hrev46368.

[pulkomandy]

Fixed in ​https://github.com/haiku/webkit/commit/035a53a95715a00aed4cfd739f5aa09c94e4233a .