fixing one problem with arrayconverter

Author: AndreSchumacher

sql/core/src/main/scala/org/apache/spark/sql/parquet/ParquetConverter.scala

@@ -275,7 +275,9 @@ class CatalystArrayConverter(
 
   // TODO: think about reusing the buffer
   override def end(): Unit = {
-    if (parent != null) parent.updateField(index, buffer)
+    assert(parent != null)
+    parent.updateField(index, buffer)
+    clearBuffer()
   }
 }
 

sql/core/src/test/scala/org/apache/spark/sql/parquet/ParquetQuerySuite.scala

@@ -405,11 +405,12 @@ class ParquetQuerySuite extends QueryTest with FunSuiteLike with BeforeAndAfterA
     assert(result(0)(3).asInstanceOf[ArrayBuffer[Any]].size === 2)
     assert(result(0)(3).asInstanceOf[ArrayBuffer[Any]].apply(0) === 2.5)
     assert(result(0)(3).asInstanceOf[ArrayBuffer[Any]].apply(1) === false)
-    assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].size === 3)
+    assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].size === 2)
+    assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].apply(0).asInstanceOf[ArrayBuffer[Any]].size === 2)
     assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].apply(1).asInstanceOf[ArrayBuffer[Any]].size === 1)
-    assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].apply(1).asInstanceOf[ArrayBuffer[ArrayBuffer[Any]]].size === 1)
-    assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].apply(1).asInstanceOf[ArrayBuffer[ArrayBuffer[Any]]].apply(0) === 9)
-    assert(true)
+    assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].apply(0).asInstanceOf[ArrayBuffer[ArrayBuffer[Any]]].apply(0).apply(0) === 7)
+    assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].apply(0).asInstanceOf[ArrayBuffer[ArrayBuffer[Any]]].apply(1).apply(0) === 8)
+    assert(result(0)(4).asInstanceOf[ArrayBuffer[Any]].apply(1).asInstanceOf[ArrayBuffer[ArrayBuffer[Any]]].apply(0).apply(0) === 9)
   }
 
   /**