Segmentation fault on Blender appdata

[bochecha]

I'm trying to update Blender in Flathub, and appstream-util crashes on the new appdata:

$ appstream-util validate _build/files/share/appdata/org.blender.Blender.appdata.xml 
_build/files/share/appdata/org.blender.Blender.appdata.xml: Segmentation fault (core dumped)

While that's probably a problem with the appdata being invalid, it would be much better if it could handle it gracefully and report the failure.

The problem happens because the new file has a <p> tag inside a <ul> tag in its <release> -> <description>:

        <release version="2.81" date="2019-11-14">
            <description>
                <p>New features:</p>
                <ul>
                    <li>Many sculpt tools and poly build tool for retopology</li>
                    <li>Voxel remesh and quad remesh</li>
                    <li>Transform origins, new snapping, mirroring and auto merge options</li>
                    <li>Revamped shaders for texturing</li>
                    <li>Cycles denoising with OpenImageDenoise and NVIDIA RTX support</li>
                    <li>Library overrides to make local overrides to linked characters and other data</li>
                </ul>
                <ul>
                <p>Enhancements:</p>
                    <li>Eevee shadows, transparency and bump mapping redesigned</li>
                    <li>Viewport options for look development with Cycles and Eevee</li>
                    <li>Finer control over rotations and scale in bones, constraints and drivers</li>
                    <li>Outliner improvements, new file browser and batch rename</li>
                </ul>
            </description>
        </release>

[bochecha]

And here's the backtrace:

Thread 2 (Thread 0x7ffff6a66700 (LWP 9)):
#0  0x00007ffff7a2d8ef in __GI___poll (fds=0x5555555ac300, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007ffff7e7022e in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x5555555ac300, timeout=<optimized out>, context=0x5555555ac470) at ../glib/gmain.c:4228
#2  0x00007ffff7e7022e in g_main_context_iterate (context=context@entry=0x5555555ac470, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:3922
#3  0x00007ffff7e70363 in g_main_context_iteration (context=0x5555555ac470, may_block=may_block@entry=1) at ../glib/gmain.c:3988
#4  0x00007ffff7e703b1 in glib_worker_main (data=<optimized out>) at ../glib/gmain.c:5868
#5  0x00007ffff7e994c1 in g_thread_proxy (data=0x5555555a9050) at ../glib/gthread.c:805
#6  0x00007ffff78175e2 in start_thread (arg=<optimized out>) at pthread_create.c:479
#7  0x00007ffff7a38413 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7ffff6d32780 (LWP 5)):
#0  0x00007ffff7a9b337 in __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:96
#1  0x00007ffff79a4716 in __vfprintf_internal (s=s@entry=0x7fffffffcc50, format=format@entry=0x7ffff7f9a721 "Tag %s in %s invalid", ap=ap@entry=0x7fffffffcdf0, mode_flags=mode_flags@entry=2) at vfprintf-internal.c:1688
#2  0x00007ffff79b63c5 in __vasprintf_internal (result_ptr=result_ptr@entry=0x7fffffffcda0, format=0x7ffff7f9a721 "Tag %s in %s invalid", format@entry=0x7fffffffcda0 "", args=0x7fffffffcdf0, args@entry=0x7ffff7f9a721, mode_flags=mode_flags@entry=2) at vasprintf.c:57
#3  0x00007ffff7a4808c in __vasprintf_chk (result_ptr=result_ptr@entry=0x7fffffffcda0, flag=flag@entry=1, format=format@entry=0x7fffffffcda0 "", ap=ap@entry=0x7ffff7f9a721) at vasprintf_chk.c:36
#4  0x00007ffff7eb7cbd in vasprintf (__ap=0x7ffff7f9a721, __fmt=0x7fffffffcda0 "", __ptr=0x7fffffffcda0) at /usr/include/x86_64-linux-gnu/bits/stdio2.h:213
#5  0x00007ffff7eb7cbd in g_vasprintf (string=string@entry=0x7fffffffcda0, format=format@entry=0x7ffff7f9a721 "Tag %s in %s invalid", args=args@entry=0x7fffffffcdf0) at ../glib/gprintf.c:330
#6  0x00007ffff7e8fdd1 in g_strdup_vprintf (format=format@entry=0x7ffff7f9a721 "Tag %s in %s invalid", args=args@entry=0x7fffffffcdf0) at ../glib/gstrfuncs.c:514
#7  0x00007ffff7e598c4 in g_error_new_valist (domain=69, code=1, format=0x7ffff7f9a721 "Tag %s in %s invalid", args=args@entry=0x7fffffffcdf0) at ../glib/gerror.c:416
#8  0x00007ffff7e59caf in g_set_error (err=err@entry=0x7fffffffd170, domain=<optimized out>, code=code@entry=1, format=format@entry=0x7ffff7f9a721 "Tag %s in %s invalid") at ../glib/gerror.c:586
#9  0x00007ffff7f805ac in as_node_get_localized_unwrap_type_ul (node=<optimized out>, error=<optimized out>, hash=<optimized out>) at ../libappstream-glib/as-node.c:345
#10 0x00007ffff7f805ac in as_node_get_localized_unwrap (node=node@entry=0x5555555abd30, error=error@entry=0x7fffffffd170) at ../libappstream-glib/as-node.c:2109
#11 0x00007ffff7f859d8 in as_release_node_parse (release=release@entry=0x5555555be080 [AsRelease], node=node@entry=0x5555555abd00, ctx=ctx@entry=0x5555555ba710, error=error@entry=0x7fffffffd170) at ../libappstream-glib/as-release.c:1013
#12 0x00007ffff7f6ce07 in as_app_node_parse_child (error=0x7fffffffd170, ctx=0x5555555ba710, flags=<optimized out>, n=0x5555555abcd0, app=0x5555555b3290 [AsApp]) at ../libappstream-glib/as-app.c:5279
#13 0x00007ffff7f6ce07 in as_app_node_parse_full (app=0x5555555b3290 [AsApp], node=<optimized out>, flags=<optimized out>, ctx=0x5555555ba710, error=0x7fffffffd170) at ../libappstream-glib/as-app.c:5429
#14 0x00007ffff7f6d9c6 in as_app_parse_data (app=0x5555555b3290 [AsApp], data=<optimized out>, flags=0, error=0x7fffffffd170) at ../libappstream-glib/as-app.c:6291
#15 0x00007ffff7f6ded6 in as_app_parse_appdata_file (error=0x7fffffffd1e0, flags=0, filename=0x7fffffffd888 "org.blender.Blender.appdata.xml", app=0x5555555b3290 [AsApp]) at ../libappstream-glib/as-app.c:6324
#16 0x00007ffff7f6ded6 in as_app_parse_file (app=app@entry=0x5555555b3290 [AsApp], filename=filename@entry=0x7fffffffd888 "org.blender.Blender.appdata.xml", flags=flags@entry=0, error=error@entry=0x7fffffffd1e0) at ../libappstream-glib/as-app.c:6386
#17 0x0000555555564218 in as_util_validate_file (error=0x7fffffffd1e0, flags=AS_APP_VALIDATE_FLAG_NONE, filename=0x7fffffffd888 "org.blender.Blender.appdata.xml") at ../client/as-util.c:2795
#18 0x0000555555564218 in as_util_validate_files (filenames=0x7fffffffd4a8, flags=AS_APP_VALIDATE_FLAG_NONE, error=0x7fffffffd278) at ../client/as-util.c:2836
#19 0x000055555555dea4 in as_util_run (error=0x7fffffffd278, values=<optimized out>, command=0x7fffffffd87f "validate", priv=0x5555555a89a0) at ../client/as-util.c:165
#20 0x000055555555dea4 in main (argc=<optimized out>, argv=<optimized out>) at ../client/as-util.c:4623

[hughsie]

I'm mad busy with RHEL 8 at the moment, but I'd gladly merge a PR if you can see the bug :)

[luyatshimbalanga]

The issue occurred on the latest stable version of Blender 2.8.2 as well.

[bochecha]

The issue occurred on the latest stable version of Blender 2.8.2 as well.

Because upstream Blender didn't fix their appdata in that release, only in master. As @hughsie said he was too busy to work on this, and as I didn't say this is way above my C proficiency, so you can see there was no fix in appstream-glib either and this issue is still open.

Even if appstream-glib didn't segfault, the upstream appdata would still be invalid, so if this is blocking your Fedora build you need to patch it manually, as I do for Flathub.

[luyatshimbalanga]

Even if appstream-glib didn't segfault, the upstream appdata would still be invalid, so if this is blocking your Fedora build you need to patch it manually, as I do for Flathub.

Noted. Manual patch applied.