Fix potential NumberFormatException when deserializing IntegerType

patch by slebresne; reviewed by jbellis for CASSANDRA-7088

CHANGES.txt

@@ -4,6 +4,7 @@
  * return all cpu values from BackgroundActivityMonitor.readAndCompute (CASSANDRA-7183)
  * fix c* launch issues on Russian os's due to output of linux 'free' cmd (CASSANDRA-6162)
  * Fix disabling autocompaction (CASSANDRA-7187)
+ * Fix potential NumberFormatException when deserializing IntegerType (CASSANDRA-7088)
 
 2.0.8
  * Correctly delete scheduled range xfers (CASSANDRA-7143)

src/java/org/apache/cassandra/db/marshal/AbstractType.java

@@ -153,8 +153,7 @@ public abstract class AbstractType<T> implements Comparator<ByteBuffer>
         TypeSerializer<T> serializer = getSerializer();
         serializer.validate(bytes);
 
-        T value = serializer.deserialize(bytes);
-        return value == null ? "null" : serializer.toString(value);
+        return serializer.toString(serializer.deserialize(bytes));
     }
 
     /** get a byte representation of the given string. */

src/java/org/apache/cassandra/serializers/InetAddressSerializer.java

@@ -65,7 +65,7 @@ public class InetAddressSerializer implements TypeSerializer<InetAddress>
 
     public String toString(InetAddress value)
     {
-        return value.getHostAddress();
+        return value == null ? "" : value.getHostAddress();
     }
 
     public Class<InetAddress> getType()

src/java/org/apache/cassandra/serializers/IntegerSerializer.java

@@ -29,12 +29,12 @@ public class IntegerSerializer implements TypeSerializer<BigInteger>
 
     public BigInteger deserialize(ByteBuffer bytes)
     {
-        return new BigInteger(ByteBufferUtil.getArray(bytes));
+        return bytes.hasRemaining() ? new BigInteger(ByteBufferUtil.getArray(bytes)) : null;
     }
 
     public ByteBuffer serialize(BigInteger value)
     {
-        return ByteBuffer.wrap(value.toByteArray());
+        return value == null ? ByteBufferUtil.EMPTY_BYTE_BUFFER : ByteBuffer.wrap(value.toByteArray());
     }
 
     public void validate(ByteBuffer bytes) throws MarshalException
@@ -44,7 +44,7 @@ public class IntegerSerializer implements TypeSerializer<BigInteger>
 
     public String toString(BigInteger value)
     {
-        return value.toString(10);
+        return value == null ? "" : value.toString(10);
     }
 
     public Class<BigInteger> getType()

src/java/org/apache/cassandra/serializers/LongSerializer.java

@@ -44,7 +44,7 @@ public class LongSerializer implements TypeSerializer<Long>
 
     public String toString(Long value)
     {
-        return String.valueOf(value);
+        return value == null ? "" : String.valueOf(value);
     }
 
     public Class<Long> getType()

src/java/org/apache/cassandra/serializers/TimestampSerializer.java

@@ -72,7 +72,7 @@ public class TimestampSerializer implements TypeSerializer<Date>
 
     public String toString(Date value)
     {
-        return FORMATTER.get().format(value);
+        return value == null ? "" : FORMATTER.get().format(value);
     }
 
     public Class<Date> getType()

src/java/org/apache/cassandra/serializers/UUIDSerializer.java

@@ -46,7 +46,7 @@ public class UUIDSerializer implements TypeSerializer<UUID>
 
     public String toString(UUID value)
     {
-        return value.toString();
+        return value == null ? "" : value.toString();
     }
 
     public Class<UUID> getType()