Launching a replxx-based application from a script results in poorly handled SIGSTOP

[theklopex]

(( I believe that Marcin Konarski died from COVID on 12/18/2021, if this is his father's X account:
https://x.com/marian_konarski/status/1604590361543905280 ))

replxx-based applications cannot handle CTRL-Z on Linux properly. This key combination sends SIGSTOP.
This situation is VERY bad if your application has multiple threads.

Steps to reproduce single-threaded:

• Compile the examples in the replxx repository.
• echo ./replxx-example-cxx-api > test.sh
• chmod 777 ./test.sh
• ./test.sh
• At the replxx> prompt, press CTRL-Z.
• It will ignore all of your remaining input, including CTRL-C. If you press CTRL-Z, then it will stop the application.
• If you run "fg" it will continue running. If you have pressed CTRL-C between the two CTRL-Z presses, then the application will receive the SIGINT and exit.

Steps to reproduce multi-threaded:

• Add code to cxx-api.cxx to create pthreads. (I created 6 threads.)
• I made my code acquire a mutex in main, then create the 6 threads.
• Each thread attempts to acquire the mutex lock. They block.
• When main is ready to return, it releases the mutex and calls pthread_join() on the six threads.
• Bottom line, the threads are doing nothing but existing.
• Perform the steps in the single-threaded issue.
• After the first CTRL-Z press, the application will not respond to any actions.
• You can attach to the PID with gdb and send SIGCONT numerous times (signal SIGCONT) and the application will eventually return to running.