Comment 93 for bug 102408

gnome_vfs_mime_application_launch_with_env calls g_spawn_async without
G_SPAWN_LEAVE_DESCRIPTORS_OPEN so helper apps should be fine with GnomeVFS.

Non-GNOME (and newer GNOME) systems without --enable-gio will use nsIProcess
which uses PR_CreateProcess, thus hitting this bug.

Helper apps should be fine in --enable-gio builds because
g_desktop_app_info_launch_uris also calls g_spawn_async without
G_SPAWN_LEAVE_DESCRIPTORS_OPEN.

For plugin/content processes this is addressed by CloseSuperfluousFds.

Most systems should have GIO these days, so it looks like the appropriate fix
here is to update glib on our build systems so we can --enable-gio.

(I haven't done an audit of other nsIProcess consumers.)