Cannot deserialize 00:00:00 from MariaDB into time::Time and chrono::NaiveTime

[leeola]

Not sure how to reproduce this, but lets start with what I do know.

Sqlx version: 0.3.5
Sqlx Features: mysql, chrono, time. [1]
Rust toolchain: nightly-2020-06-01
Database: MariaDB 10.3.18
Column type: time
Example values: 00:00:00, 02:00:00
Error message:

thread 'test_name' panicked at 'index out of bounds: the len is 0 but the index is 0', /Users/me/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/sqlx-core-0.3.5/src/io/buf.rs:55:19

I receive the above error message any time I try to query_as a MariaDB time column type into either a chrono::NaiveTime or a time::Time type. I'm also unsure about a workaround, as I can't seem deserialize that time value into a String, Vec<u8> or something comparable, either.

Thoughts?

[1]: I've used chrono and time features in combination, as well as individually.

[leeola]

I noticed that the time and chrono type tests have a micro suffix on TIME, example:

sqlx/tests/mysql/types.rs

Line 54 in a2c55b9

"TIME '05:10:20.115100'" == NaiveTime::from_hms_micro(5, 10, 20, 115100)

None of our time values have this. At least, not visibly in my queries. Could this be causing the problem?

[leeola]

Poking around blindly in the tests, with test:

    test_type!(chrono_time<NaiveTime>(
        MySql,
        "TIME '05:10:20.115100'" == NaiveTime::from_hms_micro(5, 10, 20, 115100),
        "TIME '05:10:20'" == NaiveTime::from_hms(5, 10, 20),
        "TIME '00:00:00'" == NaiveTime::from_hms(0,0,0),
        "TIME '02:00:00'" == NaiveTime::from_hms(2,0,0)
    ));

(modified from: https://github.com/launchbadge/sqlx/blob/master/tests/mysql/types.rs#L52-L55)
I got the following failure:

---- chrono::test_prepared_type_chrono_time stdout ----
thread 'chrono::test_prepared_type_chrono_time' panicked at 'assertion failed: self.remaining() >= 1', /Users/me/.rustup/toolchains/nightly-2020-06-01-x86_64-apple-darwin/lib/rustlib/src/rust/src/libcore/macros/mod.rs:10:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace


failures:
    chrono::test_prepared_type_chrono_time

With "TIME '00:00:00'" == NaiveTime::from_hms(0,0,0), being the offending line. What is the expected behavior here?

[leeola]

The culprit does seem to be these 00:00:00 times. In my application, if I select rows with 02:00:00 for example, they successfully deserialize into a chrono::NaiveTime.

[blackwolf12333]

I was looking at a similar problem with zero dates panicking on decode in #376, I can see if I can fix this too.

[blackwolf12333]

I'm actually sort of surprised this crashes on MariaDB, according to their docs this should have worked. The docs about the encoding differ from the docs on MySQL, which does say something about times with all 0. I'm implementing a fix in #460 because the DATETIME thing is a bit harder to solve because 0000-00-00 is actually an invalid value for dates so chrono doesn't like that.