Crash in g_utf8_validate

[szotsaki]

mpv version and platform

v0.29.0
built on Jul 22 2018
ffmpeg library versions:
libavutil 56.14.100
libavcodec 58.18.100
libavformat 58.12.100
libswscale 5.1.100
libavfilter 7.16.100
libswresample 3.1.100
ffmpeg version: 4.0.2

Reproduction steps

Start a radio stream which reports "icy-title" (what's currently played) and have an invalid UTF-8 character in there. In my case it was, perhaps, in another encoding.

Expected behaviour

mpv skips the invalid character.

Actual behaviour

mpv crashes with the following message:

A: 01:09:21 / 01:09:37 (99%) Cache: 16s+498KB
File tags:
 icy-title: NEK - LAURA NON C�

(process:15290): GLib-CRITICAL **: 15:09:02.059: g_variant_new_string: assertion 'g_utf8_validate (string, -1, NULL)' failed
dbus[15290]: arguments to dbus_message_iter_append_basic() were incorrect, assertion "_dbus_check_is_valid_utf8 (*string_p)" failed in file dbus-message.c line 2754.
This is normally a bug in some application using the D-Bus library.

  D-Bus not built with -rdynamic so unable to print a backtrace

I also use the MPRIS plugin.

[CounterPillow]

Looks like a problem in the mpris plugin, as mpv by itself does not use dbus.