unity-panel-service crashed with SIGSEGV in main_arena()

StacktraceTop:
 main_arena () from /lib/i386-linux-gnu/libc.so.6
 notify_cb (obj=0x9e603f8, pspec=0x9dc3000) at /build/buildd/gtk+3.0-3.1.10/./gtk/a11y/gtkwidgetaccessible.c:65
 g_cclosure_marshal_VOID__PARAM (closure=0x9e52938, return_value=0x0, n_param_values=2, param_values=0xb0c1bef0, invocation_hint=0xbfa67d00, marshal_data=0x0) at /build/buildd/glib2.0-2.29.14/./gobject/gmarshal.c:539
 g_closure_invoke (closure=0x9e52938, return_value=0x0, n_param_values=2, param_values=0xb0c1bef0, invocation_hint=0xbfa67d00) at /build/buildd/glib2.0-2.29.14/./gobject/gclosure.c:773
 signal_emit_unlocked_R (node=0x9db8cd0, detail=96, instance=0x9e603f8, emission_return=0x0, instance_and_params=0xb0c1bef0) at /build/buildd/glib2.0-2.29.14/./gobject/gsignal.c:3271

Sorry for the delay. In the end the solution was one line. panel_indicator_entry_accessible_ref_child is a implementation of atk_object_ref_child, and as the name implies, it supposes that a reference count is required.

The branch that I have just linked to this bug also add some NULL check conditions.

This bug was fixed in the package unity - 4.14.2-0ubuntu1

---------------
unity (4.14.2-0ubuntu1) oneiric; urgency=low

  * New upstream release.
    - unity crashed with AttributeError in reset_unity_compiz_profile(): 'str'
      object has no attribute 'get_string' (LP: #809378)
    - Trying to minimize Unity Dash to make it fit on a 1024x768 screen makes
      Unity freeze and then, after I log out by killing X, never start again
      (LP: #839200)
    - unity-panel-service crashed with SIGSEGV in main_arena() (LP: #817477)
    - UIFe: Panel - Indicators should be orderable regardless of their parent
      IndicatorObject (LP: #823061)
    - 'Show Desktop' fails to hand focus to desktop (LP: #836315)
    - Dash - Functionality of top left close, minimise and maximise/restore
      window decorations is confused (LP: #838875)
    - unity-panel-service Leaks Memory (LP: #779185)
    - Missing lens shortcuts (Super-A, Super-F) (LP: #834078)
    - Unity window switcher takes over <alt> key (LP: #835699)
    - update assets for window buttons (topleft) with dash opened
      (LP: #836655)
    - Where the average background colour is either very light or dark, adjust
      this value to darken/lighten in order to preserve readability
      (LP: #837993)
    - Applications don't have priority over other results (LP: #839518)
    - task tray icons are misaligned and badly sized (LP: #839354)
    - UIFe: Dash - Shape and positioning of most of the elements in the Dash
      need adjustment (LP: #841945)
    - Cannot drag applications from dash to desktop (LP: #756614)
    - systray icons still visible on each desktop in expo mode (LP: #759129)
    - transparency on unity panel broken (LP: #827012)
    - Window buttons and application menu don't autohide if left edge is
      touched (LP: #835637)
    - 'Filter results' should be right indented as in the mockups(and unity-
      2d) (LP: #838118)
    - window title should not appear until cursor leaves the menubar
      (LP: #838759)
    - Window title is not redrawn on leaving global-menu from buttons
      (LP: #839488)
    - In the dash, main text field can not be edited, except at the end
      (LP: #840862)
    - Quicklist can't be correctly hidden (LP: #843425)
    - After double clicking on the panel to restore a window, the menus won't
      be hidden on mouse-out (LP: #838021)
    - After restoring a window the application title doesn't fade-out and it
      goes below the menus (LP: #838479)
  * debian/control:
    - build-dep on latest libunity-dev for ABI/API break, nux
  * debian/rules:
    - bump shlibs, remove tweak for garantuing the version as the ABI
      is considered stable until finale now.
 -- Didier Roche <email address hidden> Thu, 08 Sep 2011 20:07:50 +0200