Comment 2 for bug 1385624

StacktraceTop:
 strrchr () at ../sysdeps/x86_64/strrchr.S:32
 _gtk_menu_tracker_item_new (observable=0x7f6d6955dc80, model=0x7f6d6955df40, item_index=0, action_namespace=0x7f6d6958c5e0 "indicator.thunderbird", is_separator=0) at /build/buildd/gtk+3.0-3.12.2/./gtk/gtkmenutrackeritem.c:524
 gtk_menu_tracker_add_items (tracker=tracker@entry=0x7f6d5400e290, change_point=change_point@entry=0x7f6d5400d698, offset=offset@entry=11, model=model@entry=0x7f6d6955df40, position=position@entry=0, n_items=0, section=0x7f6d5400d690) at /build/buildd/gtk+3.0-3.12.2/./gtk/gtkmenutracker.c:342
 gtk_menu_tracker_model_changed (model=0x7f6d6955df40, position=0, removed=0, added=1, user_data=0x7f6d5400e290) at /build/buildd/gtk+3.0-3.12.2/./gtk/gtkmenutracker.c:445
 ffi_call_unix64 () at ../src/x86/unix64.S:76