435471 - [dfb] Some parts of content area not painted when scrolled

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect)

Description

[Mohan Reddy Duggi]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008051206 Firefox/3.0
Build Identifier: Mozilla/5.0 (?;U; Linux i686;en-US;rv;1.9) Gecko/2008051317 Minefield/3.0

This is a DirectFB related bug and part of bug 422221.

When an URL is entered, the content is rendered correctly; however, when the content is scrolled, parts of content area are not painted.

Reproducible: Always

Steps to Reproduce:
1. Get mozilla-dfb sources from http://hg.mozilla.org/users/pavlov_mozilla.com/mozilla-dfb
2. gtk-dfb environment setup, mozilla-dfb build and test instructions : http://wiki.mozilla.org/Mobile/DFBPorting#DirectFB_Build_and_Test_Environment_setup
3. After launching firefox, go to any page that doesn't fit one page and scroll down and then up

Comment 1

[Ryuan Choi]

This is a Cairo-DirectFB related bug

if # of clipping box became zero,
in cairo-directfb-surface
"surface->clips = _cairo_malloc_ab (n_boxes, sizeof(DFBRegion))" failed
 
actually, the memory allocation is not necessary when the # of box is zero.

so I suggest adding below code after getting boxes on _cairo_directfb_surface_set_clip_region() in cairo-directfb-surface.c
    if(n_boxes == 0) return CAIRO_STATUS_SUCCESS;

So, now every contents are very well displyed even during scrolling. 

Comment 2

[Ryuan Choi]

Attachment: if # of box is zero, return successfully without allocation momory in _cairo_directfb_surface_set_clip_region

Comment 3

[Niranjan]

This also fixes Bug 435492.