HDFS-7676. Fix TestFileTruncate to avoid bug of HDFS-7611. Contributed by Konstantin Shvachko.

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -785,6 +785,8 @@ Release 2.7.0 - UNRELEASED
     HDFS-7659. truncate should check negative value of the new length.
     (Yi Liu via shv)
 
+    HDFS-7676. Fix TestFileTruncate to avoid bug of HDFS-7611. (shv)
+
 Release 2.6.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFileTruncate.java

@@ -496,6 +496,11 @@ public class TestFileTruncate {
    */
   @Test
   public void testTruncateEditLogLoad() throws IOException {
+    // purge previously accumulated edits
+    fs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
+    fs.saveNamespace();
+    fs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
+
     int startingFileSize = 2 * BLOCK_SIZE + BLOCK_SIZE / 2;
     int toTruncate = 1;
     final String s = "/testTruncateEditLogLoad";