HADOOP-10876. The constructor of Path should not take an empty URL as a parameter. Contributed by Zhihai Xu.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1614231 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -80,6 +80,9 @@ Release 2.6.0 - UNRELEASED
     HADOOP-10830. Missing lock in JavaKeyStoreProvider.createCredentialEntry.
     (Benoy Antony via umamahesh)
 
+    HADOOP-10876. The constructor of Path should not take an empty URL as a
+    parameter. (Zhihai Xu via wang)
+
 Release 2.5.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -129,6 +129,19 @@ public class Path implements Comparable {
     }   
   }
 
+  /** check URI parameter of Path constructor. */
+  private void checkPathArg(URI aUri) throws IllegalArgumentException {
+    // disallow construction of a Path from an empty URI
+    if (aUri == null) {
+      throw new IllegalArgumentException(
+          "Can not create a Path from a null URI");
+    }
+    if (aUri.toString().isEmpty()) {
+      throw new IllegalArgumentException(
+          "Can not create a Path from an empty URI");
+    }
+  }
+
   /** Construct a path from a String.  Path strings are URIs, but with
    * unescaped elements and some additional normalization. */
   public Path(String pathString) throws IllegalArgumentException {
@@ -176,6 +189,7 @@ public class Path implements Comparable {
    * Construct a path from a URI
    */
   public Path(URI aUri) {
+    checkPathArg(aUri);
     uri = aUri.normalize();
   }
   

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

@@ -26,11 +26,13 @@ import java.util.Arrays;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.io.AvroTestUtil;
+import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.Shell;
 
 import com.google.common.base.Joiner;
 
 import junit.framework.TestCase;
+import static org.junit.Assert.fail;
 
 public class TestPath extends TestCase {
   /**
@@ -305,6 +307,28 @@ public class TestPath extends TestCase {
     // if the child uri is absolute path
     assertEquals("foo://bar/fud#boo", new Path(new Path(new URI(
         "foo://bar/baz#bud")), new Path(new URI("/fud#boo"))).toString());
+
+    // empty URI
+    URI uri3 = new URI("");
+    assertEquals("", uri3.toString());
+    try {
+      path = new Path(uri3);
+      fail("Expected exception for empty URI");
+    } catch (IllegalArgumentException e) {
+      // expect to receive an IllegalArgumentException
+      GenericTestUtils.assertExceptionContains("Can not create a Path"
+          + " from an empty URI", e);
+    }
+    // null URI
+    uri3 = null;
+    try {
+      path = new Path(uri3);
+      fail("Expected exception for null URI");
+    } catch (IllegalArgumentException e) {
+      // expect to receive an IllegalArgumentException
+      GenericTestUtils.assertExceptionContains("Can not create a Path"
+          + " from a null URI", e);
+    }
   }
 
   /** Test URIs created from Path objects */