ImageViewer crashes

When trying to display the Ensenso images I faced a bug in pcl::visualization::ImageViewer.
The images are correctly displayed until the viewer crashes after a few (~30) seconds.

Bug log

I deleted some duplicated errors to make the log shorter

Initialising nxLib
Opening Ensenso stereo camera id = 0
ERROR: In /build/buildd/vtk-5.8.0/Filtering/vtkExecutive.cxx, line 783
vtkStreamingDemandDrivenPipeline (0x7f42a02c3fe0): UpdateInformation invoked during another request.  Returning failure to algorithm vtkImageFlip(0xf35d30).

ERROR: In /build/buildd/vtk-5.8.0/Filtering/vtkExecutive.cxx, line 783
vtkStreamingDemandDrivenPipeline (0x7f42a02c3fe0): UpdateInformation invoked during another request.  Returning failure to algorithm vtkImageFlip(0xf35d30).

ERROR: In /build/buildd/vtk-5.8.0/Filtering/vtkExecutive.cxx, line 776
vtkStreamingDemandDrivenPipeline (0x7f42a02c3fe0): ProcessRequest invoked during another request.  Returning failure to algorithm vtkImageFlip(0xf35d30) for the recursive request:
vtkInformation (0x7f42a02c5c00)
  Debug: Off
  Modified Time: 9758
  Reference Count: 1
  Registered Events: (none)
  Request: REQUEST_UPDATE_EXTENT
  FROM_OUTPUT_PORT: 0
  FORWARD_DIRECTION: 0
  ALGORITHM_BEFORE_FORWARD: 1

ERROR: In /build/buildd/vtk-5.8.0/Filtering/vtkExecutive.cxx, line 783
vtkStreamingDemandDrivenPipeline (0x7f42a02c3fe0): UpdateInformation invoked during another request.  Returning failure to algorithm vtkImageFlip(0xf35d30).

ERROR: In /build/buildd/vtk-5.8.0/Filtering/vtkExecutive.cxx, line 783
vtkStreamingDemandDrivenPipeline (0x7f42a02c3fe0): UpdateInformation invoked during another request.  Returning failure to algorithm vtkImageFlip(0xf35d30).

*** Error in `/home/dell/MEGAsync/Ensenso/pcl_ensenso_viewer/build/ensenso_pcl_images_viewer': corrupted double-linked list: 0x00007f42a031f870 ***

When trying the launch the program after the first crash:

[0;m[xcb] Unknown request in queue while dequeuing
[xcb] Most likely this is a multi-threaded client and XInitThreads has not been called
[xcb] Aborting, sorry about that.
ensenso_pcl_images_viewer: ../../src/xcb_io.c:179: dequeue_pending_request: Assertion `!xcb_xlib_unknown_req_in_deq' failed.

Test code

#include <iostream>
#include <pcl/console/print.h>
#include <pcl/io/ensenso_grabber.h>
#include <pcl/visualization/image_viewer.h>

/** @brief Convenience typedef for the Ensenso grabber callback */
typedef std::pair<pcl::PCLImage, pcl::PCLImage> PairOfImages;

/** @brief Image viewer */
pcl::visualization::ImageViewer::Ptr image_viewer_ptr;

/** @brief A pointer to the PCL Ensenso object */
pcl::EnsensoGrabber::Ptr ensenso_ptr;

/** @brief Process and/or display Ensenso grabber images
 * @param[in] images Pair of Ensenso images (raw or images with overlay)
 * @warning Image type changes if a calibration pattern is discovered/lost;
 * check @c images->first.encoding */
void
grabberCallback (const boost::shared_ptr<PairOfImages>& images)
{
  unsigned char *l_image_array = reinterpret_cast<unsigned char *> (&images->first.data[0]);
  unsigned char *r_image_array = reinterpret_cast<unsigned char *> (&images->second.data[0]);

  image_viewer_ptr->addMonoImage(l_image_array, images->first.width, images->first.height);
  //image_viewer_ptr->addRGBImage(r_image_array, images->second.width, images->second.height);
}

/** @brief Main function
 * @return Exit status */
int
main (void)
{
  image_viewer_ptr.reset (new pcl::visualization::ImageViewer);
  ensenso_ptr.reset (new pcl::EnsensoGrabber);
  ensenso_ptr->openTcpPort ();
  ensenso_ptr->openDevice ();
  ensenso_ptr->initExtrinsicCalibration (5);

  boost::function<void
  (const boost::shared_ptr<PairOfImages> &)> f = boost::bind (&grabberCallback, _1);
  ensenso_ptr->registerCallback (f);
  ensenso_ptr->start ();  // Image mode! No cloud information

  while (!image_viewer_ptr->wasStopped ())
    image_viewer_ptr->spinOnce ();

  ensenso_ptr->closeDevice ();
  return (0);
}

Sorry for the very specific test code, I don't have any other frame grabber example.
I think it has to do with the grabber threading.

Start with pcl/visualization/image_viewer.h and pcl/io/ensenso_grabber.h, then inspect the grabberCallback and the ImageViewer spinOnce loop in the supplied test code. Reproduce the sustained display and determine whether the threading interaction causes the reported crash; done means the viewer remains running without the VTK or XCB errors.