Image viewer node won't take user input if no images are published

[hidmic]

Bug report

Required Info:

• Operating System:
  • Ubuntu Bionic 18.04 (as in Nvidia OpenGL Docker image)
• Installation type:
  • Binary (debs)
• Version or commit hash:
  • Crystal pre-release.
• DDS implementation:
  • ADLink OpenSplice 6.9
• Client library (if applicable):
  • N/A

Steps to reproduce issue

Run the interprocess viewer step of the intra-process communication tutorial. Then drop the pipeline node and try to provide user input to the remaining image_viewer_node instance.

Expected behavior

image_viewer_node takes user input as documented.

Actual behavior

image_viewer_node ignores any user input and has to be terminated with a SIGINT.

Additional information

This is due to the way the node was implemented (see here).