Merge pull request #212 from yuzumika/fix-selection-underflow #minor

NPCMoreTalkHandler: don't underflow selection

src/main/java/net/packet/ByteBufInPacket.java

@@ -22,6 +22,8 @@ public class ByteBufInPacket implements InPacket {
     public byte readByte() {
         return byteBuf.readByte();
     }
+    @Override
+    public short readUnsignedByte() { return byteBuf.readUnsignedByte(); }
 
     @Override
     public short readShort() {

src/main/java/net/packet/InPacket.java

@@ -4,6 +4,7 @@ import java.awt.*;
 
 public interface InPacket extends Packet {
     byte readByte();
+    short readUnsignedByte();
     short readShort();
     int readInt();
     long readLong();

src/main/java/net/server/channel/handlers/NPCMoreTalkHandler.java

@@ -59,7 +59,7 @@ public final class NPCMoreTalkHandler extends AbstractPacketHandler {
             if (p.available() >= 4) {
                 selection = p.readInt();
             } else if (p.available() > 0) {
-                selection = p.readByte();
+                selection = p.readUnsignedByte();
             }
             if (c.getQM() != null) {
                 if (c.getQM().isStart()) {

src/test/java/net/packet/ByteBufInPacketTest.java

@@ -38,6 +38,36 @@ class ByteBufInPacketTest {
         assertEquals(writtenByte, readByte);
     }
 
+    @Test
+    void readUnsignedByte() {
+        final byte writtenByte = Byte.MAX_VALUE;
+        byteBuf.writeByte(writtenByte);
+
+        short readUnsignedByte = inPacket.readUnsignedByte();
+
+        assertEquals(writtenByte, readUnsignedByte);
+    }
+
+    @Test
+    void readUnsignedByte_shouldBeNonnegative() {
+        final byte writtenByte = Byte.MIN_VALUE;
+        byteBuf.writeByte(writtenByte);
+
+        short readUnsignedByte = inPacket.readUnsignedByte();
+
+        assertEquals((short)writtenByte + 256, readUnsignedByte);
+    }
+
+    @Test
+    void readUnsignedByte_shouldBeNonnegative2() {
+        final byte writtenByte = -1;
+        byteBuf.writeByte(writtenByte);
+
+        short readUnsignedByte = inPacket.readUnsignedByte();
+
+        assertEquals((short)writtenByte + 256, readUnsignedByte);
+    }
+
     @Test
     void readShort() {
         final short writtenShort = 12_345;