printf: %0s and %0c should fail #6030
Description
While reviewing #6028 I noticed that the format specifications %0s and %0c fail with GNU printf whereas with uutils printf they don't:
$ /usr/bin/printf "%0s"
/usr/bin/printf: %0s: invalid conversion specification
$ echo $?
1
$ /usr/bin/printf "%0c"
/usr/bin/printf: %0c: invalid conversion specification
$ echo $?
1
$ cargo run printf "%0s"
$ echo $?
0
$ cargo run printf "%0c"
$ echo $?
0