Revert "HADOOP-17430. Restore ability to set Text to empty byte array (#2545)"

This reverts commit 9e85eb9a2ef1ba2e4e19f233e0cc114dfd07a6dc.

Change-Id: Id1ac803b29931b0f643cb37bbe58534726c36f1e

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/Text.java

@@ -203,19 +203,10 @@ public class Text extends BinaryComparable
     }
   }
 
-  /**
-   * Set to a utf8 byte array. If the length of <code>utf8</code> is
-   * <em>zero</em>, actually clear {@link #bytes} and any existing
-   * data is lost.
+  /** Set to a utf8 byte array
    */
   public void set(byte[] utf8) {
-    if (utf8.length == 0) {
-      bytes = EMPTY_BYTES;
-      length = 0;
-      textLength = -1;
-    } else {
-      set(utf8, 0, utf8.length);
-    }
+    set(utf8, 0, utf8.length);
   }
   
   /** copy a text. */

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestText.java

@@ -449,22 +449,4 @@ public class TestText {
             2, Text.utf8Length(new String(new char[]{(char)254})));
   }
 
-  @Test
-  public void testSetBytes(){
-    Text a = new Text(new byte[100]);
-    assertEquals("testSetBytes100 getLength error !",
-            100, a.getLength());
-    assertEquals("testSetBytes100 getBytes.length error !",
-            100, a.getBytes().length);
-    assertEquals("testSetBytes100 getTextLength error !",
-            100, a.getTextLength());
-
-    a.set(new byte[0]);
-    assertEquals("testSetBytes0 getLength error !",
-            0, a.getLength());
-    assertEquals("testSetBytes0 getBytes.length error !",
-            0, a.getBytes().length);
-    assertEquals("testSetBytes0 getTextLength error !",
-            0, a.getTextLength());
-  }
 }