[Tuxmath-devel] tuxmath bug due to deprecated rsvg_handle_get_desc().

[Amadeus WM <ama...@ve...>]

I've been using tuxmath under (Fedora) Linux and tuxmath crashes now.
This has been going on for some time now, so in the absence of an
official fix, I looked into the problem myself. I've traced it to this: 

In t4k_loaders.c, load_svg_sprite() calls rsvg_handle_get_desc() on line 217 or so, which has been deprecated as of gnome 2.36. In my version of librsvg/rsvg-handle.c, it says that librsvg does not read the metadata/desc/title elements.

See details and backtraces below.

I've never used rsvg and I don't know its API, so I cannot fix tuxmath
beyond this point. Any chance you guys can provide a fix? I hope the
gnome changes do not require a complete rework. 

Thanks!



(gdb) bt
#0  0x00007f6260d71b17 in __rawmemchr_avx2 () at ../sysdeps/x86_64/multiarch/memchr-avx2.S:65
#1  0x00007f6260c95836 in _IO_str_init_static_internal
    (sf=sf@entry=0x7ffe36344890, ptr=ptr@entry=0x0, size=size@entry=0, pstart=pstart@entry=0x0) at strops.c:41
#2  0x00007f6260c88741 in _IO_vsscanf (string=0x0, format=0x7f6260e3cfc2 "%d", args=args@entry=0x7ffe363449c0)
    at iovsscanf.c:40
#3  0x00007f6260c82d08 in __sscanf (s=<optimized out>, format=format@entry=0x7f6260e3cfc2 "%d") at sscanf.c:32
#4  0x00007f6260e333ed in load_svg_sprite (file_name=<optimized out>, width=width@entry=-1, height=height@entry=-1)
    at t4k_loaders.c:217
#5  0x00007f6260e3455f in load_sprite
    (name=name@entry=0x430421 "comets/comet", mode=mode@entry=4, w=w@entry=-1, h=h@entry=-1, proportional=proportional@entry=false) at t4k_loaders.c:714
#6  0x00007f6260e349bc in T4K_LoadScaledSprite
    (name=name@entry=0x430421 "comets/comet", mode=mode@entry=4, width=width@entry=-1, height=height@entry=-1)
    at t4k_loaders.c:651
#7  0x00007f6260e349d0 in T4K_LoadSprite (name=name@entry=0x430421 "comets/comet", mode=mode@entry=4) at t4k_loaders.c:646
#8  0x000000000041741c in load_image_data () at fileops_media.c:213
#9  0x0000000000405790 in load_data_files () at setup.c:759
#10 0x00000000004064b3 in setup (argc=1, argv=0x7ffe363458b8) at setup.c:139
#11 0x0000000000404b89 in main (argc=<optimized out>, argv=<optimized out>) at tuxmath.c:40



Core due to sscanf being called with NULL string pointer.
  
94   sprite* load_svg_sprite(const char* file_name, int width, int height)
195  {
196    RsvgHandle* file_handle;
197    sprite* new_sprite;
<snip>
214    new_sprite->default_img = render_svg_from_handle(file_handle, width, height, "#default");
215 
216    /* get number of frames from description */
217    sscanf(rsvg_handle_get_desc(file_handle), "%d", &new_sprite->num_frames);





/**
 * rsvg_handle_get_desc:
 * @handle: An #RsvgHandle
 *
 * Returns: (nullable): This function always returns NULL.
 *
 * Since: 2.4
 *
 * Deprecated: 2.36.  Librsvg does not read the metadata/desc/title elements;
 * this function always returns #NULL.
 */
const char *
rsvg_handle_get_desc (RsvgHandle *handle)
{
    g_return_val_if_fail (handle, NULL);

    return NULL;
}