[SPARK-9421] Fix null-handling bugs in UnsafeRow.getDouble, getFloat(), and get(ordinal, dataType)

sql/catalyst/src/main/java/org/apache/spark/sql/catalyst/expressions/UnsafeRow.java

@@ -239,7 +239,7 @@ public Object get(int ordinal) {
 
   @Override
   public Object get(int ordinal, DataType dataType) {
-    if (dataType instanceof NullType) {
+    if (isNullAt(ordinal) || dataType instanceof NullType) {
       return null;
     } else if (dataType instanceof BooleanType) {
       return getBoolean(ordinal);
@@ -313,21 +313,13 @@ public long getLong(int ordinal) {
   @Override
   public float getFloat(int ordinal) {
     assertIndexIsValid(ordinal);
-    if (isNullAt(ordinal)) {
-      return Float.NaN;
-    } else {
-      return PlatformDependent.UNSAFE.getFloat(baseObject, getFieldOffset(ordinal));
-    }
+    return PlatformDependent.UNSAFE.getFloat(baseObject, getFieldOffset(ordinal));
   }
 
   @Override
   public double getDouble(int ordinal) {
     assertIndexIsValid(ordinal);
-    if (isNullAt(ordinal)) {
-      return Float.NaN;
-    } else {
-      return PlatformDependent.UNSAFE.getDouble(baseObject, getFieldOffset(ordinal));
-    }
+    return PlatformDependent.UNSAFE.getDouble(baseObject, getFieldOffset(ordinal));
   }
 
   @Override

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/UnsafeRowConverterSuite.scala

@@ -146,8 +146,8 @@ class UnsafeRowConverterSuite extends SparkFunSuite with Matchers {
     assert(createdFromNull.getShort(3) === 0)
     assert(createdFromNull.getInt(4) === 0)
     assert(createdFromNull.getLong(5) === 0)
-    assert(java.lang.Float.isNaN(createdFromNull.getFloat(6)))
-    assert(java.lang.Double.isNaN(createdFromNull.getDouble(7)))
+    assert(createdFromNull.getFloat(6) === 0.0f)
+    assert(createdFromNull.getDouble(7) === 0.0d)
     assert(createdFromNull.getUTF8String(8) === null)
     assert(createdFromNull.getBinary(9) === null)
     // assert(createdFromNull.get(10) === null)

sql/core/src/test/scala/org/apache/spark/sql/UnsafeRowSuite.scala

@@ -22,7 +22,7 @@ import java.io.ByteArrayOutputStream
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions.{UnsafeRow, UnsafeProjection}
-import org.apache.spark.sql.types.{DataType, IntegerType, StringType}
+import org.apache.spark.sql.types._
 import org.apache.spark.unsafe.PlatformDependent
 import org.apache.spark.unsafe.memory.MemoryAllocator
 import org.apache.spark.unsafe.types.UTF8String
@@ -67,4 +67,19 @@ class UnsafeRowSuite extends SparkFunSuite {
 
     assert(bytesFromArrayBackedRow === bytesFromOffheapRow)
   }
+
+  test("calling getDouble() and getFloat() on null columns") {
+    val row = InternalRow.apply(null, null)
+    val unsafeRow = UnsafeProjection.create(Array[DataType](FloatType, DoubleType)).apply(row)
+    assert(unsafeRow.getFloat(0) === row.getFloat(0))
+    assert(unsafeRow.getDouble(1) === row.getDouble(1))
+  }
+
+  test("calling get(ordinal, datatype) on null columns") {
+    val row = InternalRow.apply(null)
+    val unsafeRow = UnsafeProjection.create(Array[DataType](NullType)).apply(row)
+    for (dataType <- DataTypeTestUtils.atomicTypes) {
+      assert(unsafeRow.get(0, dataType) === null)
+    }
+  }
 }