DRILL-2567: CONVERT_FROM in where clause cause the query to fail in p…

…lanning phase

Set the writeIndex of ByteBuf returned by Unpooled.wrappedBuffer() to 0.

+ Added a unit test to exercise the code path.

contrib/storage-hbase/src/main/java/org/apache/drill/exec/store/hbase/CompareFunctionsProcessor.java

@@ -119,7 +119,7 @@ public Boolean visitConvertExpression(ConvertExpression e, LogicalExpression val
       case "UINT4":
         if (valueArg instanceof IntExpression
             && (isEqualityFn || encodingType.startsWith("U"))) {
-          bb = Unpooled.wrappedBuffer(new byte[4]).order(encodingType.endsWith("_BE") ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
+          bb = newByteBuf(4, encodingType.endsWith("_BE"));
           bb.writeInt(((IntExpression)valueArg).getInt());
         }
         break;
@@ -129,39 +129,39 @@ public Boolean visitConvertExpression(ConvertExpression e, LogicalExpression val
       case "UINT8":
         if (valueArg instanceof LongExpression
             && (isEqualityFn || encodingType.startsWith("U"))) {
-          bb = Unpooled.wrappedBuffer(new byte[8]).order(encodingType.endsWith("_BE") ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
+          bb = newByteBuf(8, encodingType.endsWith("_BE"));
           bb.writeLong(((LongExpression)valueArg).getLong());
         }
         break;
       case "FLOAT":
         if (valueArg instanceof FloatExpression && isEqualityFn) {
-          bb = Unpooled.wrappedBuffer(new byte[4]).order(ByteOrder.BIG_ENDIAN);
+          bb = newByteBuf(4, true);
           bb.writeFloat(((FloatExpression)valueArg).getFloat());
         }
         break;
       case "DOUBLE":
         if (valueArg instanceof DoubleExpression && isEqualityFn) {
-          bb = Unpooled.wrappedBuffer(new byte[8]).order(ByteOrder.BIG_ENDIAN);;
+          bb = newByteBuf(8, true);
           bb.writeDouble(((DoubleExpression)valueArg).getDouble());
         }
         break;
       case "TIME_EPOCH":
       case "TIME_EPOCH_BE":
         if (valueArg instanceof TimeExpression) {
-          bb = Unpooled.wrappedBuffer(new byte[8]).order(encodingType.endsWith("_BE") ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
+          bb = newByteBuf(8, encodingType.endsWith("_BE"));
           bb.writeLong(((TimeExpression)valueArg).getTime());
         }
         break;
       case "DATE_EPOCH":
       case "DATE_EPOCH_BE":
         if (valueArg instanceof DateExpression) {
-          bb = Unpooled.wrappedBuffer(new byte[8]).order(encodingType.endsWith("_BE") ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
+          bb = newByteBuf(8, encodingType.endsWith("_BE"));
           bb.writeLong(((DateExpression)valueArg).getDate());
         }
         break;
       case "BOOLEAN_BYTE":
         if (valueArg instanceof BooleanExpression) {
-          bb = Unpooled.wrappedBuffer(new byte[1]);
+          bb = newByteBuf(1, false /* does not matter */);
           bb.writeByte(((BooleanExpression)valueArg).getBoolean() ? 1 : 0);
         }
         break;
@@ -194,6 +194,12 @@ public Boolean visitSchemaPath(SchemaPath path, LogicalExpression valueArg) thro
     return false;
   }
 
+  private static ByteBuf newByteBuf(int size, boolean bigEndian) {
+    return Unpooled.wrappedBuffer(new byte[size])
+        .order(bigEndian ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN)
+        .writerIndex(0);
+  }
+
   private static final ImmutableSet<Class<? extends LogicalExpression>> VALUE_EXPRESSION_CLASSES;
   static {
     ImmutableSet.Builder<Class<? extends LogicalExpression>> builder = ImmutableSet.builder();

contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestHBaseFilterPushDown.java

@@ -117,6 +117,19 @@ public void testFilterPushDownConvertExpression() throws Exception {
         , 2);
   }
 
+  @Test
+  public void testFilterPushDownConvertExpressionWithNumber() throws Exception {
+    setColumnWidths(new int[] {8, 1100});
+    runHBaseSQLVerifyCount("EXPLAIN PLAN FOR\n"
+        + "SELECT\n"
+        + "  row_key\n"
+        + "FROM\n"
+        + "  hbase.`[TABLE_NAME]` tableName\n"
+        + "WHERE\n"
+        + "  convert_from(row_key, 'INT_BE') = 75"
+        , 1);
+  }
+
   @Test
   public void testFilterPushDownRowKeyLessThanOrEqualTo() throws Exception {
     setColumnWidths(new int[] {8, 74, 38});