Better EOF handling.

src/ImageSharp/Formats/Jpeg/GolangPort/Components/Decoder/DecoderThrowHelper.cs

@@ -24,8 +24,14 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
                     throw new ArgumentException("ThrowExceptionForErrorCode() called with NoError!", nameof(errorCode));
                 case OrigDecoderErrorCode.MissingFF00:
                     throw new MissingFF00Exception();
+
                 case OrigDecoderErrorCode.UnexpectedEndOfStream:
-                    throw new EOFException();
+
+                    // TODO:
+                    // Disabled for now since we want to avoid throwing for most bad eof.
+                    // Will probably delete
+                    // throw new EOFException();
+                    break;
                 default:
                     throw new ArgumentOutOfRangeException(nameof(errorCode), errorCode, null);
             }

src/ImageSharp/Formats/Jpeg/GolangPort/OrigJpegDecoderCore.cs

@@ -235,6 +235,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
 
             // Check for the Start Of Image marker.
             this.InputProcessor.ReadFull(this.Temp, 0, 2);
+
             if (this.Temp[0] != OrigJpegConstants.Markers.XFF || this.Temp[1] != OrigJpegConstants.Markers.SOI)
             {
                 throw new ImageFormatException("Missing SOI marker.");
@@ -247,6 +248,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
             while (processBytes)
             {
                 this.InputProcessor.ReadFull(this.Temp, 0, 2);
+
+                if (this.InputProcessor.ReachedEOF)
+                {
+                    // We've reached the end of the stream.
+                    processBytes = false;
+                }
+
                 while (this.Temp[0] != 0xff)
                 {
                     // Strictly speaking, this is a format error. However, libjpeg is
@@ -282,6 +290,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
                     // Section B.1.1.2 says, "Any marker may optionally be preceded by any
                     // number of fill bytes, which are bytes assigned code X'FF'".
                     marker = this.InputProcessor.ReadByte();
+
+                    if (this.InputProcessor.ReachedEOF)
+                    {
+                        // We've reached the end of the stream.
+                        processBytes = false;
+                        break;
+                    }
                 }
 
                 // End Of Image.
@@ -388,15 +403,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort
                         {
                             this.InputProcessor.Skip(remaining);
                         }
-                        else if (marker < OrigJpegConstants.Markers.SOF0)
-                        {
-                            // See Table B.1 "Marker code assignments".
-                            throw new ImageFormatException("Unknown marker");
-                        }
-                        else
-                        {
-                            throw new ImageFormatException("Unknown marker");
-                        }
 
                         break;
                 }