case of printf >fifo hang in int trap

[Alex fxmbsw7 Ratchev]

it hangs, further control-c dont take action, control-z maybe in scripts in
interactive not
so i have, mkfifo fifo ; trap 'printf nowork>fifo' int, it hangs on it, in
interactive the whole even makes all three key combos i know nowork,
control c and z and \

test:

mkfifo ${a:=/tmp/afifo}
trap 'printf hang >$a' int

first control-c is run, the rest is hanging, displaying ^C and ^\ and ^Z
but nothing happens

is this wanted behavior ?