HADOOP-8616. ViewFS configuration requires a trailing slash. Contributed by Sandy Ryza.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1392709 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -50,6 +50,9 @@ Release 2.0.3-alpha - Unreleased
     HADOOP-8855. SSL-based image transfer does not work when Kerberos
     is disabled. (todd via eli)
 
+    HADOOP-8616. ViewFS configuration requires a trailing slash. (Sandy Ryza
+    via atm)
+
 Release 2.0.2-alpha - 2012-09-07 
 
   INCOMPATIBLE CHANGES

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

@@ -89,7 +89,11 @@ class ChRootedFileSystem extends FilterFileSystem {
   public ChRootedFileSystem(final URI uri, Configuration conf)
       throws IOException {
     super(FileSystem.get(uri, conf));
-    chRootPathPart = new Path(uri.getPath());
+    String pathString = uri.getPath();
+    if (pathString.isEmpty()) {
+      pathString = "/";
+    }
+    chRootPathPart = new Path(pathString);
     chRootPathPartString = chRootPathPart.toUri().getPath();
     myUri = uri;
     workingDir = getHomeDirectory();

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

@@ -205,9 +205,13 @@ public class ViewFs extends AbstractFileSystem {
       protected
       AbstractFileSystem getTargetFileSystem(final URI uri)
         throws URISyntaxException, UnsupportedFileSystemException {
+          String pathString = uri.getPath();
+          if (pathString.isEmpty()) {
+            pathString = "/";
+          }
           return new ChRootedFs(
               AbstractFileSystem.createFileSystem(uri, config),
-              new Path(uri.getPath()));
+              new Path(pathString));
       }
 
       @Override

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

@@ -343,6 +343,15 @@ public class TestChRootedFileSystem {
     verify(mockFs).delete(eq(rawPath), eq(true));
   }
   
+  @Test
+  public void testURIEmptyPath() throws IOException {
+    Configuration conf = new Configuration();
+    conf.setClass("fs.mockfs.impl", MockFileSystem.class, FileSystem.class);
+
+    URI chrootUri = URI.create("mockfs://foo");
+    new ChRootedFileSystem(chrootUri, conf);
+  }
+
   static class MockFileSystem extends FilterFileSystem {
     MockFileSystem() {
       super(mock(FileSystem.class));

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

@@ -0,0 +1,35 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.fs.viewfs;
+
+import java.net.URI;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileContext;
+import org.apache.hadoop.fs.FsConstants;
+import org.junit.Test;
+
+public class TestViewFsURIs {
+  @Test
+  public void testURIEmptyPath() throws Exception {
+    Configuration conf = new Configuration();
+    ConfigUtil.addLink(conf, "/user", new URI("file://foo"));
+
+    FileContext.getFileContext(FsConstants.VIEWFS_URI, conf);
+  }
+}