They answer to your question is unless your using a really old version of firefox then you
cant do what your trying to do as you can see your application segfaults and it will continue to do so until you install a older version of firefox say version 1.0 - 1.4 other wise like they hundreds of others who ask this question everyday you will soon realize that if your wanting to use firefox in your application your just sol.
What i would advise that you do is follow the lead of they Gnome, Kde, Mac, Nokia, OLPC Developers.
Use one of they following.
GtkHTML
HTML rendering/printing/editing engine
http://ftp.gnome.org/pub/GNOME/sources/gtkhtml/3.15/
Gtk+ Webcore
Supports everything KHTML does or will support.
The following standards are supported by the KHTML engine:
* HTML 4.01
* CSS 1
* CSS 2.1 (screen and paged media)
* CSS 3 Selectors
* CSS 3 Other (multiple backgrounds, box-sizing and text-shadow)
* PNG, MNG, JPEG, GIF graphic formats
* DOM 1, 2 and partially 3
* ECMA-262/JavaScript 1.5
* Partial Scalable Vector Graphics support
http://gtk-webcore.sourceforge.net/index.html
WebkitGdk "Gtk+ Webcore Fork"
Same as Gtk+ Webcore but may be more stable.
http://trac.webkit.org/projects/webkit/wiki/BuildingGdk
Or you could build your own.
Start by building an html parser and then use cairo
to render the pages that your html parser parses.
Here is a tutorial on building gtk+/cairo widgets.
Part 1
http://www.gnomejournal.org/article/34/ ... -and-gtk28
Part 2
http://www.gnomejournal.org/article/36/ ... k28-part-2
Hope that helps