When MEDIA_STREAM is disable, if MediaPlayer::loadWithNextMediaEngine is called with a current engine, and there's no type specified, the next media engine that is used is the MSE one. Since there's no actually a media stream, the engine is created but never loaded. When buffered is called it tries to use its media source that is nullptr. It doesn't happen when MEDIA_STREAM is enabled, because the next media engine returned is Owr that doesn't implement buffered and always returns an empty PlatformTimeRanges. #0 0x00007f9a7db0b61b in WebCore::MediaPlayerPrivateGStreamerMSE::buffered() const [clone .localalias.94] () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #1 0x00007f9a7d5d3681 in WebCore::MediaPlayer::buffered() () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #2 0x00007f9a7d1c11db in WebCore::HTMLMediaElement::buffered() const () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #3 0x00007f9a7dbe2968 in WebCore::RenderThemeGtk::paintMediaSliderTrack(WebCore::RenderObject const&, WebCore::PaintInfo const&, WebCore::IntRect const&) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #4 0x00007f9a7d846a0d in WebCore::RenderTheme::paint(WebCore::RenderBox const&, WebCore::ControlStates&, WebCore::PaintInfo const&, WebCore::LayoutRect const&) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #5 0x00007f9a7d705f03 in WebCore::RenderBox::paintBoxDecorations(WebCore::PaintInfo&, WebCore::LayoutPoint const&) () from /home/cgarcia/src/git/gnome/WebKit/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37
Created attachment 302275 [details] Patch
Hold up. Why is a MediaPlayerPrivateGStreamerMSE ever created if MEDIA_STREAM is disabled? It sounds like we should address that design issue instead of papering over this.
Comment on attachment 302275 [details] Patch Sorry, I mixed up MEDIA_SOURCE and MEDIA_STREAM.
Committed r212815: <http://trac.webkit.org/changeset/212815>