Bug 167784

Summary: [ATK] (WebKitWebProcess:26855): GLib-GObject-WARNING **: instance with invalid (NULL) class pointer
Product: WebKit Reporter: Andres Gomez Garcia <agomez>
Component: AccessibilityAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: bugs-noreply, cgarcia, jdiggs, mcatanzaro, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: PC   
OS: Linux   
Attachments:
Description Flags
BT from gdb for the WebProcess none

Description Andres Gomez Garcia 2017-02-03 01:37:21 PST
Created attachment 300512 [details]
BT from gdb for the WebProcess

Epiphany 3.22.5 and WebKit 2.15.4.

I'm running Epiphany with the dconf key:

"process-model" = "shared-secondary-process"

And the env variable:

"export G_DEBUG=fatal-warnings"

The compilation was done with CMake args:

'-DENABLE_THREADED_COMPOSITOR=OFF -DPORT=GTK -DCMAKE_BUILD_TYPE=Release -DENABLE_MINIBROWSER=ON -DCMAKE_C_FLAGS_RELEASE="-O0 -g -DNDEBUG  -DG_DISABLE_CAST_CHECKS" -DCMAKE_CXX_FLAGS_RELEASE="-O0 -g -DNDEBUG -DG_DISABLE_CAST_CHECKS"'

After visiting several pages, eventually, the WebProcess hits a Warning.

This bug is not reproducible in a predictable way.
Comment 1 Radar WebKit Bug Importer 2017-02-03 04:00:13 PST
<rdar://problem/30346615>
Comment 2 Michael Catanzaro 2017-02-03 04:18:44 PST
Something's gone crazy wrong here. The AtkObject* axObject is non-null, and the ATK_IS_VALUE(axObject) check passes fine, but it has no class struct somehow, which is absolutely nuts. I guess it must be memory corruption somewhere, something somewhere writing zeros to the wrong place, because I don't think there's any other way a class struct could ever be NULL.