Events using &OsStr don't seem to serialize properly

[jrmuizel]

Running

use win_etw_macros::trace_logging_provider;
use std::ffi::OsStr;

#[trace_logging_provider(guid = "89d6f527-86d0-4da1-8b4b-b050159a1d96")]
pub trait MyAppEvents {
    #[event(opcode = 1)]
    fn database_connection_created(connection_id: u64, server: &OsStr);
    #[event(opcode = 2)]
    fn database_connection_closed(connection_id: u64);
    // ...
}

fn main() {
    let events = MyAppEvents::new();
    events.database_connection_created(None, 35, OsStr::new("foer"));
    events.database_connection_closed(None, 35);

shows up as

00000022    MyAppEvents 14796   14352   1   0   05\22\2020-20:41:31:607 {"connection_id":35,"server":"fo","meta":{"provider":"MyAppEvents","event":"database_connection_created","time":"2020-05-22T20:41:31.607","cpu":1,"pid":14796,"tid":14352,"channel":11,"level":4,"opcode":1}}

in TraceView. Notice that server comes out as "fo" instead of "foer".

[rylev]

I tracked this down to being caused by passing the wrong length value for a wide os string here. The comment next to the code seems to indicate that passing the number of wide chars and not the number of bytes (minus the null char) is the right thing to do, but this leads to the error reported above. When doubling this value, the correct message is displayed in TraceView.

[sivadeilra]

Thanks, I'll get this fixed.