Fix EF Core issue when using MySqlGeometry.Value

[lauxjpn]

EF Core throws an exception, when using MySqlGeometry, because there is some very general code in Microsoft.EntityFrameworkCore.Storage.Internal.DbParameterCollectionExtensions.FormatParameterValue(StringBuilder builder, object parameterValue), that is unable to handle the ReadOnlySpan<byte> type of MySqlGeometry.Value.

This PR changes the type to byte[] instead. Technically, this is a breaking change for anyone who used the Value property before. But because of the implicit cast between byte[] and ReadOnlySpan<byte>, this should be less of an issue.

In any case, if there is an issue in someones code, this change will lead to a compiler error, that can be easily fixed by replacing Value with either Value.AsSpan() or new ReadOnlySpan<byte>(Value).

[bgrainger]

Technically, this is a breaking change for anyone who used the Value property before.

I don't think MySqlGeometry gets a lot of use (see this comment: #70 (comment)), so I'm not too worried about a breaking change.

This change does make the MySqlGeometry API more compatible with Connector/NET (which does return a byte[]) but I'm not happy with returning a mutable byte[] that directly exposes the private data; this was why ReadOnlySpan<byte> was used in the first place.

And shouldn't you submit a PR to fix EFCore, adding ReadOnlySpan<byte> support in https://github.com/dotnet/efcore/blob/252dee5c84eb5d7d1ef2254974f1100f3cb9cc1a/src/EFCore.Relational/Storage/Internal/DbParameterCollectionExtensions.cs#L142-L192? 😀

[bgrainger]

I'm not happy with returning a mutable byte[] that directly exposes the private data

Fixed in afa4bf5.

[bgrainger]

Fixed in 0.69.0.

[lauxjpn]

I'm not happy with returning a mutable byte[] that directly exposes the private data; this was why ReadOnlySpan was used in the first place.

Good point!

Fixed in 0.69.0.

Thanks, that was quick!

And shouldn't you submit a PR to fix EFCore, adding ReadOnlySpan support in https://github.com/dotnet/efcore/blob/252dee5c84eb5d7d1ef2254974f1100f3cb9cc1a/src/EFCore.Relational/Storage/Internal/DbParameterCollectionExtensions.cs#L142-L192?

I am thinking about it. Might be worth it for EF Core 5.