What URL is it trying to show? Does this happen with all URLs?

As far as I can tell, any URL. But it definitely happens with GNOME
bugzilla URLs.

btw, I can confirm that this bug did/does happen - altho the problem
went away when I upgraded to redhat 8.0 (I originally had been running
Red Hat 7.2 with gnome-2-0 cvs installed to /opt/gnome2)

I had started digging around and it seemed the hang was somewhere in
gspawn.c, but unfortunately I never did find the exact problem. gdb
wasn't playing nice :-\

that said, the last time I had reproduced this was quite a few months
ago now, early in the evolution gnome2 port timeline (december or
january I think?).

note: when digging for the problem I did come accross a few places
where gspawn didn't do proper error checking on syscalls and submitted
a patch (although this did not solve it for me). perhaps there are
other places that overlook possible syscall error conditions which may
be the cause of this hang.

gspawn bug/patch:
http://bugzilla.gnome.org/show_bug.cgi?id=104825

*** Bug 114508 has been marked as a duplicate of this bug. ***

I've duped my bug to this one as I'm sure this is the cause.

Selecting Open Link in gnome-terminal caused a crash. That uses
gnome_url_show. All the other gnome_url_show applications I've tested
hang.

When gnome-terminal crashes, it produces the following errors:
PROPFIND:1: error: Extra content at the end of the document

^

GLib-GObject-ERROR **: file gtype.c: line 1593 (type_class_init_Wm):
assertion failed: (entry->vtable == NULL)
aborting...

(See also bug 114508)

I'm using libgnome 2.3.3, libgnome-vfs 2.3.3, gnome-about 2.3.2 on
Mandrake Cooker.

To reproduce:
1. Goto Applications->Desktop Preferences->Advanced-> File Types and
Programs
2. Expand the 'Internet Services'
3. Select the line with 'http' as extension
4. Click the button Remove
5. Goto Applications->Desktop Preferences->Advanced-> Preferred
Applications
-- Make sure a Web Browser is selected
6. Start gnome-about
7. Click on 'GNOME News Site'

Expected result:
Browser opens with a gnome site

Actual result:
Gnome-about hangs

The following changes will make it work:
1. Goto Applications->Desktop Preferences->Advanced-> File Types and
Programs
2. Select 'Internet Services'
3. Click 'Add Service' button
4. Type in Description field: Browser
5. Type in Protocol field: http
6. Type in Program field: galeon %s
7. Click OK button
-- Gnome-about will now work as expected (no hang), gnome-terminal
won't crash anymore

I can't reproduce this...

It seems owen checked in the patch fejj talked about. Can anyone here
still reproduce it using the latest gtk+ 2.2.x?

That patch was for glib. I have upgraded glib to 2.2.2 which includes
the patch (I've checked). I can still reproduce the crash/hang.
Someone on the Cooker mailinglist also has problems:
http://archives.mandrakelinux.com/cooker/2003-06/msg00379.php

Quoting relevant part:
""Selecting a link in gnome-terminal (laterst cooker) does one of
three things:
[1] pops up an error message saying illegal address. It does this with
   lots of addresses that used to work a day or two ago, e.g. if there
   is no http:// at the start

[2] fetches the resource at the given address and displays it in gedit

[3] makes gnome-terminal crash

If I use the capplet,
[bare foot]->Configuration->GNOME->Advanced->File Types and Programs
and choose Documents->World Wide Web->HTML page, Edit,
and change the Default Action from running links in a terminal (!!) to
Mozilla, or epiphany %s, then I can get gnome-terminal to dump core
all the time.""



I've also tried to change that default action. Mozilla seemed to work,
gvim, gnome-moz-remote, galeon and a testscript did not.
Gnome-moz-remote is set to start galeon (preference in
~/.gnome/gnome-moz-remote); the testscript is a bash script that
should echo "$@" to /tmp/abcdef.

After setting the Default Action to the testscript and selecting Open
Link, the /tmp/abcdef was not created and gnome-terminal hanged.
Setting the Default Action to gedit opened gedit.

The link I was trying to open is:
http://members.lycos.nl/bkor/test.html

In short: I now can avoid the hangs/crashes by changing the
expand_parameters function in gnome-vfs-mime-handlers.c (libgnomevfs).
Please read on for detailed guesswork and a workaround.

I copy&pasted together a small program that only calls gnome_url_show.
Even though gnome-terminal and gnome-about would crash/hang, the small
program did not. The error gnome_url_show returned was
GNOME_VFS_ERROR_NOT_SUPPORTED.

In 'File Types and Programs' I've set the Default Action to
gnome-moz-remote. Gnome adds that application to
~/.gnome/application-info/user.applications. Only Gnome does not set
'expects_uris=true' and 'supported_uri_schemes=file,http,ftp'. These
*are* already set for known applications. Testing this bug should
therefore be done with the Default Action set to an application Gnome
doesn't already know about. Note that adding 'expects_uris' and
'supported_uri_schemes' will only work around the bug. Also, remove in
'File Types and Programs' the 'http' service under 'Internet Services'.

After doing all of the above, gnome_url_show should return the
GNOME_VFS_ERROR_NOT_SUPPORTED error. In the small application this
works ok, but it causes crashes/hangs in the bigger applications
(gnome-terminal/gnome-about). I've tested gnome-about and determined
that gnome-about hangs when returning from the function
'href_item_event_callback'. This function calls gnome_url_show. When I
added a call to 'show_error_dialog' it caused gnome-about to crash.

After the above, I guessed gnome_url_show somehow corrupts memory and
it is related to the GNOME_VFS_ERROR_NOT_SUPPORTED. The error is
returned in the expand_parameters function in
gnome-vfs-mime-handlers.c (libgnomevfs). A small part of that function:
2141:  g_strfreev (c_argv);
2142:  g_strfreev (r_argv);
2143:  return GNOME_VFS_ERROR_NOT_SUPPORTED;

Commenting out line 2141, line 2142, or line 2141 & 2142 avoids the
crashes/hangs in gnome-terminal and gnome-about.

Hope this helps. Don't forget that lines 2079-2081 look the same (to
me) and may have the same bug.

Thanks a lot for that investigation. The problem was indeed the free
in the error case. I fixed this in gnome-vfs HEAD.

I've rebuilded gnome-vfs 2.3.4 with your changes. Gnome-terminal and
gnome-about now work as expected (no hangs/crashes).

Please mark it verified fixed (I do not have the required permissions).

Thanks