Some panic cases found by afl.rs #1010
Description
I've using afl.rs to fuzz this crate. And I've found several APIs may panic due to arithmetic overflow.
The code to replay these panics are
let _local0 = chrono::naive::NaiveDateTime::from_timestamp_opt(-4227854320, 1678774288);
let _local1 = chrono::Duration::microseconds(-7019067213869040);
let _local2_param0_helper1 = _local0.unwrap();
chrono::DurationRound::duration_trunc(_local2_param0_helper1, _local1);
let _local0 = chrono::naive::NaiveDateTime::from_timestamp_opt(320041586, 1920103021);
let _local1 = chrono::Duration::nanoseconds(-8923838508697114584);
let _local2_param0_helper1 = _local0.unwrap();
chrono::DurationRound::duration_round(_local2_param0_helper1, _local1);
let _local0 = chrono::naive::NaiveDateTime::from_timestamp_opt(-2621440, 0);
let _local1 = chrono::Duration::nanoseconds(-9223372036854771421);
let _local2_param0_helper1 = _local0.unwrap();
chrono::DurationRound::duration_round(_local2_param0_helper1, _local1);
let _local0 = chrono::naive::NaiveDateTime::from_timestamp_opt(-502509993984, 64);
let _local1_param0_helper1 = _local0.unwrap();
chrono::Datelike::with_ordinal0(&(_local1_param0_helper1), 4294967295);
let _local0 = chrono::naive::NaiveDateTime::from_timestamp_opt(-754576364, 336909572);
let _local1_param0_helper1 = _local0.unwrap();
chrono::Datelike::with_day0(&(_local1_param0_helper1), 4294967295);
let _local0 = chrono::naive::NaiveDateTime::from_timestamp(-8377300, 742391807);
chrono::Datelike::with_month0(&(_local0), 4294967295);
chrono::Datelike::with_month(&(_local0), 4294967295);
let _local0 = chrono::naive::NaiveDateTime::from_timestamp(-11676614656, 15282199);
chrono::naive::NaiveDateTime::timestamp_nanos(&(&_local0));
Besides, I've found an not a char boundary error. The code to replay the panic is
chrono::naive::NaiveDateTime::parse_from_str("\u{c}SUN\u{e}\u{3000}\0m@J\u{3000}\0\u{3000}\0m\u{c}!\u{c}\u{b}\u{c}\u{c}\u{c}\u{c}%A\u{c}\u{b}\0SU\u{c}\u{c}",
"\u{c}\u{c}%A\u{c}\u{b}\0SUN\u{c}\u{c}\u{c}SUNN\u{c}\u{c}\u{c}SUN\u{c}\u{c}!\u{c}\u{b}\u{c}\u{c}\u{c}\u{c}%A\u{c}\u{b}%a");
let _local1 = chrono::offset::FixedOffset::east_opt(17367308);
let _local2_param0_helper1 = _local1.unwrap();
chrono::offset::Offset::fix(&(_local2_param0_helper1));
The simple bug report is like this.
I hope you will check if this is an actually bug. Thanks a lot.