Bug 2099334

What happens if you run:

$ WEBKIT_DISABLE_COMPOSITING_MODE=1 yelp

Does that fix the video?

It does not fix the video.

Nevertheless I made some debugging attempt ($ export GST_DEBUG="3,webkit*:6" GST_DEBUG_FILE="$HOME/gst.log" GST_DEBUG_NO_COLOR=1 WEBKIT_FORCE_SANDBOX=0) and cough this excerpt with ERRORs (full debug log in attachment):

0:00:00.146036288  4822 0x561c5fcb4600 DEBUG      webkitmediaplayer MediaPlayerPrivateGStreamer.cpp:1840:operator(): got missing plugin installation callback with result 203
0:00:00.146095073  4822 0x561c5fcb4600 WARN               structure gststructure.c:1863:priv_gst_structure_append_to_gstring: No value transform to serialize field 'gerror' of type 'GError'
0:00:00.146122003  4822 0x561c5fcb4600 ERROR           webkitcommon GStreamerCommon.cpp:466:operator():<media-player-0> Got message: error message: 0x561c60385cb0, time 99:99:99.999999999, seq-num 59, element 'uridecodebin0', GstMessageError, gerror=(GError)NULL, debug=(string)"gsturidecodebin.c\(1409\):\ gen_source_element\ \(\):\ /GstPlayBin:media-player-0/GstURIDecodeBin:uridecodebin0";
0:00:00.146147649  4822 0x561c5fcb4600 LOG        webkitmediaplayer MediaPlayerPrivateGStreamer.cpp:1708:handleMessage:<media-player-0> Message error received from element uridecodebin0
0:00:00.146180206  4822 0x561c5fcb4600 WARN               structure gststructure.c:1863:priv_gst_structure_append_to_gstring: No value transform to serialize field 'gerror' of type 'GError'
0:00:00.146202578  4822 0x561c5fcb4600 ERROR           webkitcommon GStreamerCommon.cpp:466:operator():<media-player-1> Got message: error message: 0x561c603a0a30, time 99:99:99.999999999, seq-num 139, element 'uridecodebin1', GstMessageError, gerror=(GError)NULL, debug=(string)"gsturidecodebin.c\(1409\):\ gen_source_element\ \(\):\ /GstPlayBin:media-player-1/GstURIDecodeBin:uridecodebin1";
0:00:00.146224398  4822 0x561c5fcb4600 LOG        webkitmediaplayer MediaPlayerPrivateGStreamer.cpp:1708:handleMessage:<media-player-1> Message error received from element uridecodebin1
0:00:00.146254924  4822 0x561c5fcb4600 ERROR      webkitmediaplayer MediaPlayerPrivateGStreamer.cpp:1714:handleMessage: Error 12: No URI handler implemented for "bogus-help". (url=bogus-help:/gnome-help/figures/gnome-task-switching.webm)
0:00:00.146349303  4822 0x561c5fcb4600 WARN               structure gststructure.c:1863:priv_gst_structure_append_to_gstring: No value transform to serialize field 'gerror' of type 'GError'
0:00:00.146389031  4822 0x561c5fcb4600 ERROR           webkitcommon GStreamerCommon.cpp:466:operator():<media-player-2> Got message: error message: 0x561c603b21c0, time 99:99:99.999999999, seq-num 219, element 'uridecodebin2', GstMessageError, gerror=(GError)NULL, debug=(string)"gsturidecodebin.c\(1409\):\ gen_source_element\ \(\):\ /GstPlayBin:media-player-2/GstURIDecodeBin:uridecodebin2";
0:00:00.146428686  4822 0x561c5fcb4600 LOG        webkitmediaplayer MediaPlayerPrivateGStreamer.cpp:1708:handleMessage:<media-player-2> Message error received from element uridecodebin2
0:00:00.146452332  4822 0x561c5fcb4600 ERROR      webkitmediaplayer MediaPlayerPrivateGStreamer.cpp:1714:handleMessage: Error 12: No URI handler implemented for "bogus-help". (url=bogus-help:/gnome-help/figures/gnome-windows-and-workspaces.webm)


those ERRORs are not present in debug log with working webkit2gtk3-2.34.6-1.el8.x86_64 version.

I think this is an upstream bug, but we never noticed because all the videos have long since been removed from the upstream user help. The affected code is https://gitlab.gnome.org/GNOME/yelp/-/blob/gnome-3-28/libyelp/yelp-uri-builder.c

Upstream thinks it might be caused by https://github.com/WebKit/WebKit/commit/e414eb4401d6fdeedc70fe7a27129d9d0489b55b. If not, I will probably have to bisect WebKit to see when it broke.

(In reply to Michael Catanzaro from comment #5)
> Upstream thinks it might be caused by
> https://github.com/WebKit/WebKit/commit/
> e414eb4401d6fdeedc70fe7a27129d9d0489b55b. If not, I will probably have to
> bisect WebKit to see when it broke.

It's not that commit. I am bisecting.

Upstream: https://bugs.webkit.org/show_bug.cgi?id=242156

It looks like a one-line change, so hopefully will be easy to solve.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: webkit2gtk3 security and bug fix update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2022:7704