HADOOP-9924. Merging addendum change r1520903 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1520909 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileUtil.java

@@ -1239,6 +1239,9 @@ public class FileUtil {
     List<String> classPathEntryList = new ArrayList<String>(
       classPathEntries.length);
     for (String classPathEntry: classPathEntries) {
+      if (classPathEntry.length() == 0) {
+        continue;
+      }
       if (classPathEntry.endsWith("*")) {
         // Append all jars that match the wildcard
         Path globPath = new Path(classPathEntry).suffix("{.jar,.JAR}");

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestFileUtil.java

@@ -757,7 +757,7 @@ public class TestFileUtil {
     String wildcardPath = tmp.getCanonicalPath() + File.separator + "*";
     String nonExistentSubdir = tmp.getCanonicalPath() + Path.SEPARATOR + "subdir"
       + Path.SEPARATOR;
-    List<String> classPaths = Arrays.asList("cp1.jar", "cp2.jar", wildcardPath,
+    List<String> classPaths = Arrays.asList("", "cp1.jar", "cp2.jar", wildcardPath,
       "cp3.jar", nonExistentSubdir);
     String inputClassPath = StringUtils.join(File.pathSeparator, classPaths);
     String classPathJar = FileUtil.createJarWithClassPath(inputClassPath,
@@ -776,6 +776,9 @@ public class TestFileUtil {
       Assert.assertNotNull(classPathAttr);
       List<String> expectedClassPaths = new ArrayList<String>();
       for (String classPath: classPaths) {
+        if (classPath.length() == 0) {
+          continue;
+        }
         if (wildcardPath.equals(classPath)) {
           // add wildcard matches
           for (File wildcardMatch: wildcardMatches) {