looking for consistent C-c trap behavior

[gentoo_eshoes]

I've noticed that if I trap SIGINT in a bash script, the behavior when 
encountering C-c depends on whether an external command (eg. 'sleep 100') or a 
builtin command (like 'read -p') was encountered.

I attach an example script which requires me to press C-c twice to interrupt 
the builtin 'read -p' command, and it only works because I'm restoring the trap 
via 'trap - SIGINT' the first time.

My goal is to have C-c interrupt and use that exit code (130 most likely) to 
exit with from script, regardless or whether or not the interrupted command in 
the script was an internal or external one.

How to do?

Thanks.