2005-01-27 Michael Koch <konqueror@gmx.de>

	* java/util/zip/ZipFile.java
	(ZIP_MAGIC): New constant.
	(ZipFile): Check if given file is really a zip file.
	(checkZipFile): New method.
	(checkClosed): New method.
	(entries): Check if file was closed. Return an empty enumeration in
	error case.
	(getEntries): Use checkClosed().
	(getEntry): Check if file was closed.
	(getInputStream): Likewise.
	(size): Likewise.

2 files changed, 59 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index 2e76b103f..c6796422d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2005-01-27  Michael Koch  <konqueror@gmx.de>
+
+	* java/util/zip/ZipFile.java
+	(ZIP_MAGIC): New constant.
+	(ZipFile): Check if given file is really a zip file.
+	(checkZipFile): New method.
+	(checkClosed): New method.
+	(entries): Check if file was closed. Return an empty enumeration in
+	error case.
+	(getEntries): Use checkClosed().
+	(getEntry): Check if file was closed.
+	(getInputStream): Likewise.
+	(size): Likewise.
+
 2005-01-27  Patrik Reali  <reali@acm.org>
 
 	* doc/www.gnu.org/faq/faq.wml: current command to generate doc
diff --git a/java/util/zip/ZipFile.java b/java/util/zip/ZipFile.java
index b8773d578..18a508717 100644
--- a/java/util/zip/ZipFile.java
+++ b/java/util/zip/ZipFile.java
@@ -1,5 +1,6 @@
 /* ZipFile.java --
-   Copyright (C) 2001, 2002, 2003, 2004  Free Software Foundation, Inc.
+   Copyright (C) 2001, 2002, 2003, 2004, 2005
+   Free Software Foundation, Inc.
 
 This file is part of GNU Classpath.
 
@@ -38,6 +39,8 @@ exception statement from your version. */
 
 package java.util.zip;
 
+import gnu.java.util.EmptyEnumeration;
+
 import java.io.BufferedInputStream;
 import java.io.DataInput;
 import java.io.EOFException;
@@ -94,6 +97,7 @@ public class ZipFile implements ZipConstants
   {
     this.raf = new RandomAccessFile(name, "r");
     this.name = name;
+    checkZipFile();
   }
 
   /**
@@ -106,6 +110,7 @@ public class ZipFile implements ZipConstants
   {
     this.raf = new RandomAccessFile(file, "r");
     this.name = file.getPath();
+    checkZipFile();
   }
 
   /**
@@ -135,6 +140,28 @@ public class ZipFile implements ZipConstants
       }
     this.raf = new RandomAccessFile(file, "r");
     this.name = file.getPath();
+    checkZipFile();
+  }
+
+  private void checkZipFile() throws IOException, ZipException
+  {
+    byte[] magicBuf = new byte[4];
+    raf.read(magicBuf);
+
+    if (readLeInt(magicBuf, 0) != LOCSIG)
+      {
+	raf.close();
+	throw new ZipException("Not a valid zip file");
+      }
+  }
+
+  /**
+   * Checks if file is closed and throws an exception.
+   */
+  private void checkClosed()
+  {
+    if (closed)
+      throw new IllegalStateException("ZipFile has closed: " + name);
   }
 
   /**
@@ -312,16 +339,20 @@ public class ZipFile implements ZipConstants
 
   /**
    * Returns an enumeration of all Zip entries in this Zip file.
+   *
+   * @exception IllegalStateException when the ZipFile has already been closed
    */
   public Enumeration entries()
   {
+    checkClosed();
+    
     try
       {
 	return new ZipEntryEnumeration(getEntries().values().iterator());
       }
     catch (IOException ioe)
       {
-	return null;
+	return EmptyEnumeration.getInstance();
       }
   }
 
@@ -335,8 +366,7 @@ public class ZipFile implements ZipConstants
   {
     synchronized(raf)
       {
-	if (closed)
-	  throw new IllegalStateException("ZipFile has closed: " + name);
+	checkClosed();
 
 	if (entries == null)
 	  readEntries();
@@ -351,9 +381,13 @@ public class ZipFile implements ZipConstants
    * @param the name. May contain directory components separated by
    * slashes ('/').
    * @return the zip entry, or null if no entry with that name exists.
+   *
+   * @exception IllegalStateException when the ZipFile has already been closed
    */
   public ZipEntry getEntry(String name)
   {
+    checkClosed();
+
     try
       {
 	HashMap entries = getEntries();
@@ -423,11 +457,14 @@ public class ZipFile implements ZipConstants
    * @param entry the entry to create an InputStream for.
    * @return the input stream, or null if the requested entry does not exist.
    *
+   * @exception IllegalStateException when the ZipFile has already been closed
    * @exception IOException if a i/o error occured.
    * @exception ZipException if the Zip archive is malformed.  
    */
   public InputStream getInputStream(ZipEntry entry) throws IOException
   {
+    checkClosed();
+
     HashMap entries = getEntries();
     String name = entry.getName();
     ZipEntry zipEntry = (ZipEntry) entries.get(name);
@@ -459,9 +496,13 @@ public class ZipFile implements ZipConstants
 
   /**
    * Returns the number of entries in this zip file.
+   *
+   * @exception IllegalStateException when the ZipFile has already been closed
    */
   public int size()
   {
+    checkClosed();
+    
     try
       {
 	return getEntries().size();