svn merge -c 1365224 FIXES: HADOOP-8606. FileSystem.get may return the wrong filesystem (Daryn Sharp via bobby)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1365228 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -114,6 +114,9 @@ Release 0.23.3 - UNRELEASED
     HADOOP-8599. Non empty response from FileSystem.getFileBlockLocations when
     asking for data beyond the end of file. (Andrey Klochkov via todd)
 
+    HADOOP-8606. FileSystem.get may return the wrong filesystem (Daryn Sharp
+    via bobby)
+
 Release 0.23.2 - UNRELEASED 
 
   NEW FEATURES

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

@@ -270,11 +270,11 @@ public abstract class FileSystem extends Configured implements Closeable {
     String scheme = uri.getScheme();
     String authority = uri.getAuthority();
 
-    if (scheme == null) {                       // no scheme: use default FS
+    if (scheme == null && authority == null) {     // use default FS
       return get(conf);
     }
 
-    if (authority == null) {                       // no authority
+    if (scheme != null && authority == null) {     // no authority
       URI defaultUri = getDefaultUri(conf);
       if (scheme.equals(defaultUri.getScheme())    // if scheme matches default
           && defaultUri.getAuthority() != null) {  // & default has authority

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

@@ -34,8 +34,8 @@ import org.junit.Test;
 import java.security.PrivilegedExceptionAction;
 import java.util.concurrent.Semaphore;
 
+import static org.junit.Assert.*;
 import static org.mockito.Mockito.mock;
-import static junit.framework.Assert.assertTrue;
 
 
 public class TestFileSystemCaching {
@@ -49,6 +49,65 @@ public class TestFileSystemCaching {
     assertSame(fs1, fs2);
   }
 
+  static class DefaultFs extends LocalFileSystem {
+    URI uri;
+    @Override
+    public void initialize(URI uri, Configuration conf) {
+      this.uri = uri;
+    }
+    @Override
+    public URI getUri() {
+      return uri;
+    }
+  }
+  
+  @Test
+  public void testDefaultFsUris() throws Exception {
+    final Configuration conf = new Configuration();
+    conf.set("fs.defaultfs.impl", DefaultFs.class.getName());
+    final URI defaultUri = URI.create("defaultfs://host");
+    FileSystem.setDefaultUri(conf, defaultUri);
+    FileSystem fs = null;
+    
+    // sanity check default fs
+    final FileSystem defaultFs = FileSystem.get(conf);
+    assertEquals(defaultUri, defaultFs.getUri());
+    
+    // has scheme, no auth
+    fs = FileSystem.get(URI.create("defaultfs:/"), conf);
+    assertSame(defaultFs, fs);
+    fs = FileSystem.get(URI.create("defaultfs:///"), conf);
+    assertSame(defaultFs, fs);
+    
+    // has scheme, same auth
+    fs = FileSystem.get(URI.create("defaultfs://host"), conf);
+    assertSame(defaultFs, fs);
+    
+    // has scheme, different auth
+    fs = FileSystem.get(URI.create("defaultfs://host2"), conf);
+    assertNotSame(defaultFs, fs);
+    
+    // no scheme, no auth
+    fs = FileSystem.get(URI.create("/"), conf);
+    assertSame(defaultFs, fs);
+    
+    // no scheme, same auth
+    try {
+      fs = FileSystem.get(URI.create("//host"), conf);
+      fail("got fs with auth but no scheme");
+    } catch (Exception e) {
+      assertEquals("No FileSystem for scheme: null", e.getMessage());
+    }
+    
+    // no scheme, different auth
+    try {
+      fs = FileSystem.get(URI.create("//host2"), conf);
+      fail("got fs with auth but no scheme");
+    } catch (Exception e) {
+      assertEquals("No FileSystem for scheme: null", e.getMessage());
+    }
+  }
+  
   public static class InitializeForeverFileSystem extends LocalFileSystem {
     final static Semaphore sem = new Semaphore(0);
     public void initialize(URI uri, Configuration conf) throws IOException {