Icon/Image from Stream doesn't work for partial reads

[stephentoub]

Repro:

using System.Drawing;

byte[] ico;
using (var hc = new HttpClient())
{
    ico = await new HttpClient().GetByteArrayAsync(@"https://raw.githubusercontent.com/dotnet/runtime/main/src/native/corehost/dotnet/dotnet.ico");
}

var stream = new TrickleStream(ico);
new Icon(stream);

class TrickleStream : MemoryStream
{
    public TrickleStream(byte[] bytes) : base(bytes) { }

    public override int Read(byte[] buffer, int offset, int count) =>
        base.Read(buffer, offset, Math.Min(count, 1));
    public override int Read(Span<byte> buffer) =>
        base.Read(buffer.IsEmpty ? buffer : buffer.Slice(0, 1));
}

This should successfully load the data from the Stream into the icon, but instead it throws an exception.

All of these should be updated to not assume Stream.Read will return as much data as was requested.

runtime/src/libraries/System.Drawing.Common/src/System/Drawing/Icon.cs

Line 75 in 1928cd2

f.Read(_iconData, 0, _iconData.Length);

runtime/src/libraries/System.Drawing.Common/src/System/Drawing/Icon.cs

Line 113 in 1928cd2

stream.Read(_iconData, 0, _iconData.Length);

runtime/src/libraries/System.Drawing.Common/src/System/Drawing/Icon.cs

Line 130 in 1928cd2

stream.Read(_iconData, 0, _iconData.Length);

runtime/src/libraries/System.Drawing.Common/src/System/Drawing/Image.cs

Line 1057 in 1928cd2

dataStream.Read(image._rawData, 0, (int)dataStream.Length);

cc: @eerhardt

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Issue Details

---

Repro:

using System.Drawing;

byte[] ico;
using (var hc = new HttpClient())
{
    ico = await new HttpClient().GetByteArrayAsync(@"https://raw.githubusercontent.com/dotnet/runtime/main/src/native/corehost/dotnet/dotnet.ico");
}

var stream = new TrickleStream(ico);
new Icon(stream);

class TrickleStream : MemoryStream
{
    public TrickleStream(byte[] bytes) : base(bytes) { }

    public override int Read(byte[] buffer, int offset, int count) =>
        base.Read(buffer, offset, Math.Min(count, count));
    public override int Read(Span<byte> buffer) =>
        base.Read(buffer.IsEmpty ? buffer : buffer.Slice(0, 1));
}

This should successfully load the data from the Stream into the icon, but instead it throws an exception.

All of these should be updated to not assume Stream.Read will return as much data as was requested.

runtime/src/libraries/System.Drawing.Common/src/System/Drawing/Icon.cs

Line 75 in 1928cd2

f.Read(_iconData, 0, _iconData.Length);

runtime/src/libraries/System.Drawing.Common/src/System/Drawing/Icon.cs

Line 113 in 1928cd2

stream.Read(_iconData, 0, _iconData.Length);

runtime/src/libraries/System.Drawing.Common/src/System/Drawing/Icon.cs

Line 130 in 1928cd2

stream.Read(_iconData, 0, _iconData.Length);

runtime/src/libraries/System.Drawing.Common/src/System/Drawing/Image.cs

Line 1057 in 1928cd2

dataStream.Read(image._rawData, 0, (int)dataStream.Length);

Author:	stephentoub
Assignees:	-
Labels:	area-System.Drawing
Milestone:	-

[stephentoub]

Related:
#69159

[ViktorHofer]

cc @JeremyKuhne