User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0
In PARI-2.8.1 which was just released, idealappr() no longer takes a
"flag" argument. I thought that PARI/GP cared a lot about backwards
compatibility, so it is surprising to remove this flag, which was never
even deprecated. So it would be more logical to keep the flag, but
deprecate it (like the flag in matkerint).