[drum-sampler] crash when moving the inpoint about otto HOT 3 CLOSED

* thread #1: tid = 0x6f59ac, 0x00000001000961a8 otto`void otto::ui::vg::Canvas::plotLines<std::__1::__wrap_iter<otto::ui::vg::Point const*> >(this=0x00007fff5fbfe638, first=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfc970, last=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfc968) + 440 at canvas.hpp:460, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x11142a000)
    frame #0: 0x00000001000961a8 otto`void otto::ui::vg::Canvas::plotLines<std::__1::__wrap_iter<otto::ui::vg::Point const*> >(this=0x00007fff5fbfe638, first=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfc970, last=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfc968) + 440 at canvas.hpp:460
   457 	      if (first == last) return;
   458
   459 	      moveTo(*first++);
-> 460 	      for (auto p : util::sequence(first, last)) {
   461 	        lineTo(p);
   462 	      }
   463 	    }

* thread #1: tid = 0x6f59ac, 0x00000001000961a8 otto`void otto::ui::vg::Canvas::plotLines<std::__1::__wrap_iter<otto::ui::vg::Point const*> >(this=0x00007fff5fbfe638, first=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfc970, last=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfc968) + 440 at canvas.hpp:460, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x11142a000)
  * frame #0: 0x00000001000961a8 otto`void otto::ui::vg::Canvas::plotLines<std::__1::__wrap_iter<otto::ui::vg::Point const*> >(this=0x00007fff5fbfe638, first=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfc970, last=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfc968) + 440 at canvas.hpp:460
    frame #1: 0x0000000100096309 otto`auto otto::engines::DrumSampleScreen::draw(this=0x00007fff5fbfcdb8, ctx=0x00007fff5fbfe638, f=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfca38, l=__wrap_iter<const otto::ui::vg::Point *> @ 0x00007fff5fbfca30)::$_5::operator()() const::'lambda0'(otto::ui::vg::Canvas&, std::__1::__wrap_iter<otto::ui::vg::Point const*>, std::__1::__wrap_iter<otto::ui::vg::Point const*>)::operator()<otto::ui::vg::Canvas, std::__1::__wrap_iter<otto::ui::vg::Point const*>, std::__1::__wrap_iter<otto::ui::vg::Point const*> >(otto::ui::vg::Canvas&, std::__1::__wrap_iter<otto::ui::vg::Point const*>, std::__1::__wrap_iter<otto::ui::vg::Point const*>) const + 57 at drum-sampler.cpp:564
    frame #2: 0x00000001000962c2 otto`_ZNSt3__16invokeIZZN4otto7engines16DrumSampleScreen4drawERNS1_2ui2vg6CanvasEENK3$_5clEvEUlRT_T0_T1_E0_JS7_NS_11__wrap_iterIPKNS5_5PointEEESI_EEENS_9result_ofIFOS9_DpOT0_EE4typeESK_SN_ [inlined] _ZNSt3__18__invokeIZZN4otto7engines16DrumSampleScreen4drawERNS1_2ui2vg6CanvasEENK3$_5clEvEUlRT_T0_T1_E0_JS7_NS_11__wrap_iterIPKNS5_5PointEEESI_EEEDTclclsr3std3__1E7forwardIS9_Efp_Espclsr3std3__1E7forwardIT0_Efp0_EEEOS9_DpOSJ_(__f=0x00007fff5fbfcdb8, __args=0x00007fff5fbfe638, __args=0x00007fff5fbfcb88, __args=0x00007fff5fbfcb70) + 178 at type_traits:4323
    frame #3: 0x0000000100096277 otto`_ZNSt3__16invokeIZZN4otto7engines16DrumSampleScreen4drawERNS1_2ui2vg6CanvasEENK3$_5clEvEUlRT_T0_T1_E0_JS7_NS_11__wrap_iterIPKNS5_5PointEEESI_EEENS_9result_ofIFOS9_DpOT0_EE4typeESK_SN_(__f=0x00007fff5fbfcdb8, __args=0x00007fff5fbfe638, __args=0x00007fff5fbfcb88, __args=0x00007fff5fbfcb70) + 103 at functional:2361
    frame #4: 0x0000000100095ee6 otto`_ZN4otto2ui7widgets8WaveformINS_4util9dyn_arrayIfEEE10draw_rangeIZZNS_7engines16DrumSampleScreen4drawERNS0_2vg6CanvasEENK3$_5clEvEUlRT_T0_T1_E0_EEvSC_NS3_5audio7SectionIiEEOSE_(this=0x0000000100709370, ctx=0x00007fff5fbfe638, subrange=(in = 3200, out = 0), p=0x00007fff5fbfcdb8) + 1286 at waveform_widget.hpp:191
    frame #5: 0x00000001000957db otto`otto::engines::DrumSampleScreen::draw(this=0x000000010071b7f8)::$_5::operator()() const + 235 at drum-sampler.cpp:562
    frame #6: 0x00000001000956dd otto`void std::__1::__invoke_void_return_wrapper<void>::__call<otto::engines::DrumSampleScreen::draw(otto::ui::vg::Canvas&)::$_5&>(otto::engines::DrumSampleScreen::draw(otto::ui::vg::Canvas&)::$_5&&&) [inlined] decltype(__f=0x000000010071b7f8)::$_5&>(fp)(std::__1::forward<>(fp0))) std::__1::__invoke<otto::engines::DrumSampleScreen::draw(otto::ui::vg::Canvas&)::$_5&>(otto::engines::DrumSampleScreen::draw(otto::ui::vg::Canvas&)::$_5&&&) + 45 at type_traits:4323
    frame #7: 0x00000001000956cc otto`void std::__1::__invoke_void_return_wrapper<void>::__call<otto::engines::DrumSampleScreen::draw(__args=0x000000010071b7f8)::$_5&>(otto::engines::DrumSampleScreen::draw(otto::ui::vg::Canvas&)::$_5&&&) + 28 at __functional_base:349
    frame #8: 0x0000000100095559 otto`std::__1::__function::__func<otto::engines::DrumSampleScreen::draw(otto::ui::vg::Canvas&)::$_5, std::__1::allocator<otto::engines::DrumSampleScreen::draw(otto::ui::vg::Canvas&)::$_5>, void ()>::operator(this=0x000000010071b7f0)() + 41 at functional:1562
    frame #9: 0x0000000100042b4b otto`std::__1::function<void ()>::operator(this=0x00007fff5fbfd2d0)() const + 123 at functional:1924
    frame #10: 0x00000001000880fb otto`otto::ui::vg::Canvas::callAt(this=0x00007fff5fbfe638, p=(x = 22.2000008, y = 197.899994), f=0x00007fff5fbfd2d0)> const&) + 75 at canvas.hpp:384
    frame #11: 0x00000001000856e1 otto`otto::engines::DrumSampleScreen::draw(this=0x0000000100709360, ctx=0x00007fff5fbfe638) + 1825 at drum-sampler.cpp:553
    frame #12: 0x000000010007e87c otto`otto::ui::impl::draw_frame(ctx=0x00007fff5fbfe638) + 108 at mainui.cpp:58
    frame #13: 0x0000000100076388 otto`otto::ui::main_ui_loop() + 1832 at glfw-impl.cpp:744
    frame #14: 0x00000001000058e5 otto`main(argc=1, argv=0x00007fff5fbff5b0) + 725 at main.cpp:52
    frame #15: 0x00007fff9bf945ad libdyld.dylib`start + 1