Sync ProtonJ2 with upstream

Author: acogoluegnes

src/main/qpid/org/apache/qpid/protonj2/codec/decoders/ProtonDecoder.java

@@ -535,7 +535,7 @@ public Integer readInteger(ProtonBuffer buffer, DecoderState state) throws Decod
 
         switch (encodingCode) {
             case EncodingCodes.SMALLINT:
-                return buffer.readByte() & 0xff;
+                return (int) buffer.readByte();
             case EncodingCodes.INT:
                 return buffer.readInt();
             case EncodingCodes.NULL:
@@ -551,7 +551,7 @@ public int readInteger(ProtonBuffer buffer, DecoderState state, int defaultValue
 
         switch (encodingCode) {
             case EncodingCodes.SMALLINT:
-                return buffer.readByte() & 0xff;
+                return buffer.readByte();
             case EncodingCodes.INT:
                 return buffer.readInt();
             case EncodingCodes.NULL:

src/main/qpid/org/apache/qpid/protonj2/codec/decoders/primitives/Integer8TypeDecoder.java

@@ -80,7 +80,7 @@ public int readPrimitiveValue(InputStream stream, StreamDecoderState state) thro
 
     @Override
     public Integer readValue(ProtonBuffer buffer, DecoderState state) throws DecodeException {
-        return buffer.readByte() & 0xff;
+        return Integer.valueOf(buffer.readByte());
     }
 
     @Override

src/main/qpid/org/apache/qpid/protonj2/codec/decoders/primitives/Long8TypeDecoder.java

@@ -32,7 +32,7 @@ public final class Long8TypeDecoder extends LongTypeDecoder {
 
     @Override
     public Long readValue(ProtonBuffer buffer, DecoderState state) throws DecodeException {
-        return (long) buffer.readByte() & (byte) 0xff;
+        return (long) buffer.readByte();
     }
 
     @Override