Pull request overview

This PR moves conversion/session state (text encoding, time zone, and other ParameterStatus-driven values) from PgSerializerOptions to a per-connector PgConversionContext, and threads that context through binding/reading/writing so Npgsql can react to mid-session state changes (notably client_encoding and TimeZone).

Changes:

• Introduces per-connection NpgsqlConnector.ConversionContext, rotates it on relevant ParameterStatus updates, and updates reader/writer/binding call sites to use it.
• Adjusts type binding (PgConcreteTypeInfo) to distinguish invariant vs context-dependent descriptors and re-resolve buffer requirements at runtime when needed.
• Updates NodaTime legacy timestamp-tz converters to resolve time zone at read-time from the connection context instead of capturing it at type-mapping creation time.

Reviewed changes

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Pull request overview

Copilot reviewed 28 out of 28 changed files in this pull request and generated no new comments.

src/Npgsql/BackendMessages/RowDescriptionMessage.cs:360

• FieldDescription.GetInfoAndBind can return a cached _objectConversionContext that was built against a prior PgConversionContext when called with type==typeof(object) and DataFormat != Text. Since PgConversionContext instances are rotated on ParameterStatus updates (client_encoding/TimeZone), this can serve stale BufferRequirement data. Consider routing any access to the object-typed cache through GetObjectConversionContext(conversionContext) (at least when type is null or typeof(object)), rather than using _objectConversionContext directly.

        if (result is { IsDefault: false, TypeInfo.Type: var typeToConvert } && typeToConvert == type)
            return;

        var objectInfo = DataFormat is DataFormat.Text && type is not null ? GetObjectConversionContext(conversionContext) : _objectConversionContext;
        if (objectInfo.TypeInfo is not null && (typeof(object) == type || objectInfo.TypeInfo.Type == type))
        {
            result = objectInfo;
            return;

Pull request overview

Copilot reviewed 28 out of 28 changed files in this pull request and generated 4 comments.

Pull request overview

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src/Npgsql/BackendMessages/RowDescriptionMessage.cs:366

• FieldDescription.GetInfoAndBind can return a cached _objectConversionContext that was resolved against an older PgConversionContext: when type != null and DataFormat != Text, objectInfo is taken directly from _objectConversionContext (line 362) and returned for object/matching types without checking SourceContext. After a client_encoding/TimeZone rotation, this can reuse stale BufferRequirement/binding. Consider ensuring that any returned objectInfo was resolved against the supplied conversionContext (e.g., call GetObjectConversionContext(conversionContext) whenever type != null, or explicitly check ReferenceEquals(objectInfo.SourceContext, conversionContext) before using _objectConversionContext).

        var objectInfo = DataFormat is DataFormat.Text && type is not null ? GetObjectConversionContext(conversionContext) : _objectConversionContext;
        if (objectInfo.TypeInfo is not null && (typeof(object) == type || objectInfo.TypeInfo.Type == type))
        {
            result = objectInfo;
            return;

Pull request overview

Copilot reviewed 28 out of 28 changed files in this pull request and generated no new comments.

src/Npgsql/NpgsqlParameter.cs:756

• Bind is idempotent via _isBound, but it doesn’t validate that the cached _binding was produced against the same PgConversionContext instance passed in. After a mid-session client_encoding/TimeZone rotation the connector replaces ConversionContext, and reusing a binding computed under the old context can yield an incorrect size (e.g. string byte count differs between UTF-8 and WIN1252), which can corrupt the bind message/protocol framing. Consider storing the source PgConversionContext on the parameter binding (similar to ReadConversionContext.SourceContext) and forcing DisposeBindingState()/rebind when it differs (or when relevant fields changed).

    /// Bind the current value to the type info, truncate (if applicable), take its size, and do any final validation before writing.
    internal void Bind(PgConversionContext conversionContext, out DataFormat format, out Size size, DataFormat? requiredFormat = null)
    {
        if (TypeInfo is null || ConcreteTypeInfo is null)
            ThrowHelper.ThrowInvalidOperationException($"Missing type info, {nameof(ResolveTypeInfo)} needs to be called before {nameof(Bind)}.");

        // Invalidate a cached binding whose format no longer matches what the caller requires —
        // the type info may still support the required format, just not the format the cached
        // binding chose. Re-running Bind with the new preference can produce a satisfying binding.
        if (_isBound && requiredFormat is not null && _binding.DataFormat != requiredFormat.GetValueOrDefault())
        {
            DisposeBindingState();

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Pull request overview

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Pull request overview

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Pull request overview

Copilot reviewed 34 out of 34 changed files in this pull request and generated 1 comment.

Pull request overview

Copilot reviewed 34 out of 34 changed files in this pull request and generated 2 comments.

Pull request overview

Copilot reviewed 34 out of 34 changed files in this pull request and generated 1 comment.

Pull request overview

Copilot reviewed 34 out of 34 changed files in this pull request and generated 1 comment.

Pull request overview

Copilot reviewed 34 out of 34 changed files in this pull request and generated no new comments.