CI failures caused by NestedServer.applies_display_config_on_startup memory error (invalid read of size 8)

12:10:32 11: [ RUN ] NestedServer.applies_display_config_on_startup
12:10:32 11: [2016-08-03 12:10:32.254941] mirserver: Starting
12:10:32 11: [2016-08-03 12:10:32.256803] mirserver: Selected driver: mir:stub-graphics (version 0.25.0)
12:10:32 11: [2016-08-03 12:10:32.260847] mirserver: Using software cursor
12:10:32 11: [2016-08-03 12:10:32.282496] mirserver: Selected input driver: mir:stub-input (version: 0.25.0)
12:10:32 11: [2016-08-03 12:10:32.283421] mirserver: Mir version 0.25.0
12:10:32 11: [2016-08-03 12:10:32.332147] mirserver: Starting
12:10:32 11: [2016-08-03 12:10:32.454335] mirserver: Using nested cursor
12:10:32 11: [2016-08-03 12:10:32.504765] mirserver: Initial display configuration:
12:10:32 11: [2016-08-03 12:10:32.505625] mirserver: 1.1: VGA 0.0" 0x0mm
12:10:32 11: [2016-08-03 12:10:32.505887] mirserver: Current mode 640x480 60.00Hz
12:10:32 11: [2016-08-03 12:10:32.506133] mirserver: Preferred mode 640x480 60.00Hz
12:10:32 11: [2016-08-03 12:10:32.506341] mirserver: Logical position +0+0
12:10:32 11: [2016-08-03 12:10:32.506978] mirserver: 1.2: VGA 0.0" 0x0mm
12:10:32 11: [2016-08-03 12:10:32.507230] mirserver: Current mode 1920x1080 60.00Hz
12:10:32 11: [2016-08-03 12:10:32.507475] mirserver: Preferred mode 1920x1080 60.00Hz
12:10:32 11: [2016-08-03 12:10:32.507690] mirserver: Logical position +640+0
12:10:32 11: [2016-08-03 12:10:32.521401] mirserver: Mir version 0.25.0
12:10:32 11: [2016-08-03 12:10:32.650729] mirserver: Stopping
12:10:32 11: ==11247== Thread 11 Input dispatch:
12:10:32 11: ==11247== Invalid read of size 8
12:10:32 11: ==11247== at 0x4116330: mir::graphics::nested::detail::DisplayBuffer::event_thunk(MirSurface*, MirEvent const*, void*) (display_buffer.cpp:109)
12:10:32 11: ==11247== by 0x4E6BDBD: std::_Function_handler<void (MirEvent*), std::function<void (MirEvent const*)> >::_M_invoke(std::_Any_data const&, MirEvent*&&) (functional:2267)
12:10:32 11: ==11247== by 0x4EA007F: mir::input::receiver::android::InputReceiver::process_and_maybe_send_event() [clone .constprop.55] (functional:2267)
12:10:32 11: ==11247== by 0x50E2209: operator() (functional:2267)
12:10:32 11: ==11247== by 0x50E2209: (anonymous namespace)::DispatchableAdaptor::dispatch(unsigned int) [clone .lto_priv.445] (multiplexing_dispatchable.cpp:57)
12:10:32 11: ==11247== by 0x50E330C: mir::dispatch::MultiplexingDispatchable::dispatch(unsigned int) (multiplexing_dispatchable.cpp:210)
12:10:32 11: ==11247== by 0x50E330C: mir::dispatch::MultiplexingDispatchable::dispatch(unsigned int) (multiplexing_dispatchable.cpp:210)
12:10:32 11: ==11247== by 0x50F250E: (anonymous namespace)::dispatch_loop(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::shared_ptr<mir::dispatch::ThreadedDispatcher::ThreadShutdownRequestHandler>, std::shared_ptr<mir::dispatch::Dispatchable>, std::function<void ()> const&) [clone .lto_priv.314] (threaded_dispatcher.cpp:211)
12:10:32 11: ==11247== by 0x50EACFD: _M_invoke (functional:1531)
12:10:32 11: ==11247== by 0x50EACFD: operator() (functional:1520)
12:10:32 11: ==11247== by 0x50EACFD: std::thread::_Impl<std::_Bind_simple<void (*(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::shared_ptr<mir::dispatch::ThreadedDispatcher::ThreadShutdownRequestHandler>, std::shared_ptr<mir::dispatch::MultiplexingDispatchable>, std::function<void ()>))(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::shared_ptr<mir::dispatch::ThreadedDispatcher::ThreadShutdownRequestHandler>, std::shared_ptr<mir::dispatch::Dispatchable>, std::function<void ()> const&)> >::_M_run() (thread:115)
12:10:32 11: ==11247== by 0x586496F: ??? (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.22)
12:10:32 11: ==11247== by 0x5D4F709: start_thread (pthread_create.c:333)
12:10:32 11: ==11247== by 0x606B6AC: clone (clone.S:109)
12:10:32 11: ==11247== Address 0xe043c20 is 64 bytes inside a block of size 136 free'd
12:10:32 11: ==11247== at 0x4C2F24B: operator delete(void*) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
12:10:32 11: ==11247== by 0x41125B8: _M_release (shared_ptr_base.h:150)
12:10:33 11: ==11247== by 0x41125B8: __base_dtor (shared_ptr_base.h:659)
12:10:33 11: ==11247== by 0x41125B8: __base_dtor (shared_ptr_base.h:925)
12:10:33 11: ==11247== by 0x41125B8: __base_dtor (shared_ptr.h:93)
12:10:33 11: ==11247== by 0x41125B8: __base_dtor (stl_pair.h:96)
12:10:33 11: ==11247== by 0x41125B8: destroy (new_allocator.h:124)
12:10:33 11: ==11247== by 0x41125B8: destroy (alloc_traits.h:542)
12:10:33 11: ==11247== by 0x41125B8: std::__detail::_Hashtable_alloc<std::allocator<std::__detail::_Hash_node<std::pair<mir::IntWrapper<mir::frontend::detail::SessionsBufferStreamIdTag, int> const, std::shared_ptr<mir::frontend::ClientBufferTracker> >, true> > >::_M_deallocate_node(std::__detail::_Hash_node<std::pair<mir::IntWrapper<mir::frontend::detail::SessionsBufferStreamIdTag, int> const, std::shared_ptr<mir::frontend::ClientBufferTracker> >, true>*) [clone .isra.50] [clone .lto_priv.2001] (hashtable_policy.h:1973)
12:10:33 11: ==11247== by 0x4119877: _M_deallocate_nodes (hashtable_policy.h:1986)
12:10:33 11: ==11247== by 0x4119877: clear (hashtable.h:1914)
12:10:33 11: ==11247== by 0x4119877: std::_Hashtable<mir::IntWrapper<mir::frontend::detail::SessionsBufferStreamIdTag, int>, std::pair<mir::IntWrapper<mir::frontend::detail::SessionsBufferStreamIdTag, int> const, std::shared_ptr<mir::frontend::ClientBufferTracker> >, std::allocator<std::pair<mir::IntWrapper<mir::frontend::detail::SessionsBufferStreamIdTag, int> const, std::shared_ptr<mir::frontend::ClientBufferTracker> > >, std::__detail::_Select1st, std::equal_to<mir::IntWrapper<mir::frontend::detail::SessionsBufferStreamIdTag, int> >, std::hash<mir::IntWrapper<mir::frontend::detail::SessionsBufferStreamIdTag, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::~_Hashtable() (hashtable.h:1225)
12:10:33 11: ==11247== by 0x4107FB6: __base_dtor (unordered_map.h:98)
12:10:33 11: ==11247== by 0x4107FB6: mir::graphics::nested::Display::~Display() (display.cpp:203)
12:10:33 11: ==11247== by 0x4108058: mir::graphics::nested::Display::~Display() (display.cpp:208)
12:10:33 11: ==11247== by 0x41410E5: std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release() [clone .constprop.1483] (shared_ptr_base.h:150)
12:10:33 11: ==11247== by 0x4141860: __base_dtor (shared_ptr_base.h:659)
12:10:33 11: ==11247== by 0x4141860: __base_dtor (shared_ptr_base.h:925)
12:10:33 11: ==11247== by 0x4141860: __base_dtor (shared_ptr.h:93)
12:10:33 11: ==11247== by 0x4141860: __base_dtor (display_server.cpp:44)
12:10:33 11: ==11247== by 0x4141860: mir::DisplayServer::~DisplayServer() [clone .constprop.1461] (display_server.cpp:200)
12:10:33 11: ==11247== by 0x40B39DF: mir::run_mir(mir::ServerConfiguration&, std::function<void (mir::DisplayServer&)>, std::function<void (int)> const&) (run_mir.cpp:98)
12:10:33 11: ==11247== by 0x4089425: mir::Server::run() (server.cpp:454)
12:10:33 11: ==11247== by 0x53C693: operator() (async_server_runner.cpp:88)
12:10:33 11: ==11247== by 0x53C693: _M_invoke<> (functional:1531)
12:10:33 11: ==11247== by 0x53C693: operator() (functional:1520)
12:10:33 11: ==11247== by 0x53C693: std::thread::_Impl<std::_Bind_simple<mir_test_framework::AsyncServerRunner::start_server()::{lambda()#2} ()> >::_M_run() (thread:115)
12:10:33 11: ==11247== by 0x586496F: ??? (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.22)
12:10:33 11: ==11247== by 0x5D4F709: start_thread (pthread_create.c:333)
12:10:33 11: ==11247== by 0x606B6AC: clone (clone.S:109)
12:10:33 11: ==11247== Block was alloc'd at
12:10:33 11: ==11247== at 0x4C2E0EF: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
12:10:33 11: ==11247== by 0x410523E: mir::graphics::nested::Display::create_surfaces(mir::graphics::DisplayConfiguration const&)::{lambda(mir::graphics::OverlappingOutputGroup const&)#1}::operator()(mir::graphics::OverlappingOutputGroup const&) const [clone .lto_priv.2107] (new_allocator.h:104)
12:10:33 11: ==11247== by 0x41DCD83: operator() (functional:2267)
12:10:33 11: ==11247== by 0x41DCD83: mir::graphics::OverlappingOutputGrouping::for_each_group(std::function<void (mir::graphics::OverlappingOutputGroup const&)> const&) (overlapping_output_grouping.cpp:92)
12:10:33 11: ==11247== by 0x412BB25: mir::graphics::nested::Display::create_surfaces(mir::graphics::DisplayConfiguration const&) [clone .constprop.842] (display.cpp:321)
12:10:33 11: ==11247== by 0x41082F1: mir::graphics::nested::Display::Display(std::shared_ptr<mir::graphics::Platform> const&, std::shared_ptr<mir::graphics::nested::HostConnection> const&, std::shared_ptr<mir::graphics::DisplayReport> const&, std::shared_ptr<mir::graphics::DisplayConfigurationPolicy> const&, std::shared_ptr<mir::graphics::GLConfig> const&) (display.cpp:200)
12:10:33 11: ==11247== by 0x4116ED6: make_module_ptr (module_deleter.h:100)
12:10:33 11: ==11247== by 0x4116ED6: mir::graphics::nested::Platform::create_display(std::shared_ptr<mir::graphics::DisplayConfigurationPolicy> const&, std::shared_ptr<mir::graphics::GLConfig> const&) (platform.cpp:51)
12:10:33 11: ==11247== by 0x40E38B5: operator() (default_configuration.cpp:151)
12:10:33 11: ==11247== by 0x40E38B5: std::_Function_handler<std::shared_ptr<mir::graphics::Display> (), mir::DefaultServerConfiguration::the_display()::{lambda()#1}>::_M_invoke(std::_Any_data const&) [clone .lto_priv.2430] (functional:1857)
12:10:33 11: ==11247== by 0x40EC042: operator() (functional:2267)
12:10:33 11: ==11247== by 0x40EC042: mir::CachedPtr<mir::MainLoop>::operator()(std::function<std::shared_ptr<mir::MainLoop> ()>) (cached_ptr.h:41)
12:10:33 11: ==11247== by 0x4134C06: mir::DefaultServerConfiguration::the_display() (default_configuration.cpp:154)
12:10:33 11: ==11247== by 0x40B36E1: __base_ctor (display_server.cpp:58)
12:10:33 11: ==11247== by 0x40B36E1: __base_ctor (display_server.cpp:189)
12:10:33 11: ==11247== by 0x40B36E1: mir::run_mir(mir::ServerConfiguration&, std::function<void (mir::DisplayServer&)>, std::function<void (int)> const&) (run_mir.cpp:98)
12:10:33 11: ==11247== by 0x4089425: mir::Server::run() (server.cpp:454)
12:10:33 11: ==11247== by 0x53C693: operator() (async_server_runner.cpp:88)
12:10:33 11: ==11247== by 0x53C693: _M_invoke<> (functional:1531)
12:10:33 11: ==11247== by 0x53C693: operator() (functional:1520)
12:10:33 11: ==11247== by 0x53C693: std::thread::_Impl<std::_Bind_simple<mir_test_framework::AsyncServerRunner::start_server()::{lambda()#2} ()> >::_M_run() (thread:115)
12:10:33 11: ==11247== by 0x586496F: ??? (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.22)
12:10:33 11: ==11247== by 0x5D4F709: start_thread (pthread_create.c:333)
12:10:33 11: ==11247== by 0x606B6AC: clone (clone.S:109)
12:10:33 11: ==11247==
12:10:33 11: [2016-08-03 12:10:32.774153] mirserver: Stopping
12:10:33 11: [ OK ] NestedServer.applies_display_config_on_startup (615 ms)

As seen in: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=yakkety/1700/consoleFull