Bug 168662 – [GStreamer] Crash in MediaPlayerPrivateGStreamerMSE::buffered() when MEDIA_STREAM is disabled

• Status: RESOLVED
• Resolution: FIXED
• Component: Platform

[Carlos Garcia Campos]

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

[Carlos Garcia Campos]

Created attachment 302275 [details]
Patch

[Michael Catanzaro]

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.

[Michael Catanzaro]

Comment on attachment 302275 [details]
Patch

Sorry, I mixed up MEDIA_SOURCE and MEDIA_STREAM.

[Carlos Garcia Campos]

Committed r212815: <http://trac.webkit.org/changeset/212815>