From ec5cdb2fe394b6a8ca3d30b7652049f39c1aecdb Mon Sep 17 00:00:00 2001 From: Andrew Kelley Date: Tue, 22 Jul 2025 17:06:25 -0700 Subject: [PATCH] std: fix deprecated writer not handling the buffer --- lib/std/Io.zig | 7 ++++++- lib/std/Io/DeprecatedWriter.zig | 7 ++++++- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/std/Io.zig b/lib/std/Io.zig index b27217ece0..3f98ec3043 100644 --- a/lib/std/Io.zig +++ b/lib/std/Io.zig @@ -419,9 +419,14 @@ pub fn GenericWriter( new_interface: Writer, err: ?Error = null, - fn drain(w: *Writer, data: []const []const u8, splat: usize) Writer.Error!usize { + fn drain(w: *std.io.Writer, data: []const []const u8, splat: usize) std.io.Writer.Error!usize { _ = splat; const a: *@This() = @alignCast(@fieldParentPtr("new_interface", w)); + const buffered = w.buffered(); + if (buffered.len != 0) return w.consume(a.derp_writer.write(buffered) catch |err| { + a.err = err; + return error.WriteFailed; + }); return a.derp_writer.write(data[0]) catch |err| { a.err = err; return error.WriteFailed; diff --git a/lib/std/Io/DeprecatedWriter.zig b/lib/std/Io/DeprecatedWriter.zig index 391b985357..81774b357c 100644 --- a/lib/std/Io/DeprecatedWriter.zig +++ b/lib/std/Io/DeprecatedWriter.zig @@ -100,7 +100,12 @@ pub const Adapter = struct { fn drain(w: *std.io.Writer, data: []const []const u8, splat: usize) std.io.Writer.Error!usize { _ = splat; - const a: *@This() = @fieldParentPtr("new_interface", w); + const a: *@This() = @alignCast(@fieldParentPtr("new_interface", w)); + const buffered = w.buffered(); + if (buffered.len != 0) return w.consume(a.derp_writer.write(buffered) catch |err| { + a.err = err; + return error.WriteFailed; + }); return a.derp_writer.write(data[0]) catch |err| { a.err = err; return error.WriteFailed;