Arch Linux

Additional info:
* package version(s): bc 1.07-1


Steps to reproduce:

create a file "foobar.bc" with this line as content: foobar = read();
run "echo 1 | bc -q foobar.bc"

bc will spin at 100% CPU load. A strace log ends with

read(0, "1\n", 4096) = 2
read(0, "", 4096) = 0
read(0, "", 4096) = 0
read(0, "", 4096) = 0

where it reads the 1 just like it should, but then it spins on reading empty strings forever.

With bc 1.06 the same bc script works without issues.

I don't know if this is an upstream bug or something with readline/edline/whatever specifically in Archlinux.

This also breaks building the kernel, because make prepare runs echo 300 | bc -q kernel/time/timeconst.bc which then spins forever on read().