vp9dec: error: Failed to decode frame

I just pulled latest changes with VP9 alpha channel support and got errors when stopping pipeline that can be reproduced with this simple pipeline:

GST_DEBUG=3 gst-launch-1.0 \
    filesrc location=colour_hearts_720p.webm ! \
    matroskademux ! \
    decodebin ! \
    identity eos-after=100 ! \
    fakesink

The output is:

Setting pipeline to PAUSED ...
0:00:00.007848676   367 0x564edc6bd0d0 WARN                 basesrc gstbasesrc.c:3688:gst_base_src_start_complete:<filesrc0> pad not activated yet
Pipeline is PREROLLING ...
0:00:00.008178500   367 0x564edc6ba920 WARN                ebmlread ebml-read.c:622:gst_ebml_read_utf8:<matroskademux0> Invalid UTF-8 string at offset 551

(gst-launch-1.0:367): GStreamer-WARNING **: 12:13:53.821: Trying to set string on taglist field 'extended-comment', but string is not valid UTF-8. Please file a bug.
0:00:00.009806388   367 0x564edc6ba920 WARN      matroskareadcommon matroska-read-common.c:711:gst_matroska_read_common_parse_skip:<matroskademux0:sink> Unknown CueTrackPositions subelement 0xf0 - ignoring
0:00:00.009814994   367 0x564edc6ba920 WARN      matroskareadcommon matroska-read-common.c:711:gst_matroska_read_common_parse_skip:<matroskademux0:sink> Unknown CueTrackPositions subelement 0xf0 - ignoring
0:00:00.009820555   367 0x564edc6ba920 WARN      matroskareadcommon matroska-read-common.c:711:gst_matroska_read_common_parse_skip:<matroskademux0:sink> Unknown CueTrackPositions subelement 0xf0 - ignoring
0:00:00.009825514   367 0x564edc6ba920 WARN      matroskareadcommon matroska-read-common.c:711:gst_matroska_read_common_parse_skip:<matroskademux0:sink> Unknown CueTrackPositions subelement 0xf0 - ignoring
0:00:00.010654361   367 0x564edc6baf60 FIXME           videodecoder gstvideodecoder.c:1106:gst_video_decoder_drain_out:<vp9dec0> Sub-class should implement drain()
0:00:00.010659160   367 0x7f1538092000 FIXME           videodecoder gstvideodecoder.c:1106:gst_video_decoder_drain_out:<vp9dec1> Sub-class should implement drain()
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
0:00:00.098265413   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098278938   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098295239   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098298425   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098320968   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098324815   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098363548   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098367105   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098378937   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098383606   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098434242   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098437568   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098447787   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098450773   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098470440   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098473276   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098489626   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098492271   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098523871   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098527418   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
0:00:00.098538228   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4505:_gst_video_decoder_error:<vp9dec0> error: Failed to decode frame
0:00:00.098540984   367 0x564edc6baf60 WARN            videodecoder gstvideodecoder.c:4507:_gst_video_decoder_error:<vp9dec0> error: corrupt frame
ERROR: from element /GstPipeline:pipeline0/GstDecodeBin:decodebin0/GstVp9AlphaDecodeBin:vp9alphadecodebin0/GstVP9Dec:vp9dec0: Failed to decode frame
Additional debug info:
../ext/vpx/gstvpxdec.c(718): gst_vpx_dec_handle_frame (): /GstPipeline:pipeline0/GstDecodeBin:decodebin0/GstVp9AlphaDecodeBin:vp9alphadecodebin0/GstVP9Dec:vp9dec0:
corrupt frame
Execution ended after 0:00:00.084791963
Setting pipeline to NULL ...
0:00:00.098637235   367 0x564edc6ba920 WARN           matroskademux matroska-demux.c:6049:gst_matroska_demux_loop:<matroskademux0> error: Internal data stream error.
0:00:00.098645150   367 0x564edc6ba920 WARN           matroskademux matroska-demux.c:6049:gst_matroska_demux_loop:<matroskademux0> error: streaming stopped, reason error (-5)
ERROR: from element /GstPipeline:pipeline0/GstMatroskaDemux:matroskademux0: Internal data stream error.
Additional debug info:
../gst/matroska/matroska-demux.c(6049): gst_matroska_demux_loop (): /GstPipeline:pipeline0/GstMatroskaDemux:matroskademux0:
streaming stopped, reason error (-5)
Freeing pipeline ...

Example file with VP9 and alpha channel: colour_hearts_720p