diff --git a/src/main/org/apache/tools/bzip2/CBZip2OutputStream.java b/src/main/org/apache/tools/bzip2/CBZip2OutputStream.java
index b2ad87e09..b4922a859 100644
--- a/src/main/org/apache/tools/bzip2/CBZip2OutputStream.java
+++ b/src/main/org/apache/tools/bzip2/CBZip2OutputStream.java
@@ -613,7 +613,7 @@ public class CBZip2OutputStream extends OutputStream implements BZip2Constants {
                 }
 
                 if (ge > gs && nPart != nGroups && nPart != 1
-                    && ((nGroups - nPart) % 2 == 1)) {
+                    && ((nGroups - nPart) % 2 != 0)) {
                     aFreq -= mtfFreq[ge];
                     ge--;
                 }
@@ -983,9 +983,7 @@ public class CBZip2OutputStream extends OutputStream implements BZip2Constants {
             b = t;
         }
         if (b > c) {
-            t = b;
             b = c;
-            c = t;
         }
         if (a > b) {
             b = a;
@@ -1030,7 +1028,7 @@ public class CBZip2OutputStream extends OutputStream implements BZip2Constants {
 
             med = med3(block[zptr[lo] + d + 1],
                        block[zptr[hi            ] + d  + 1],
-                       block[zptr[(lo + hi) >> 1] + d + 1]);
+                       block[zptr[(lo + hi) >>> 1] + d + 1]);
 
             unLo = ltLo = lo;
             unHi = gtHi = hi;
diff --git a/src/main/org/apache/tools/tar/TarInputStream.java b/src/main/org/apache/tools/tar/TarInputStream.java
index c17d6d0da..f6c126ce4 100644
--- a/src/main/org/apache/tools/tar/TarInputStream.java
+++ b/src/main/org/apache/tools/tar/TarInputStream.java
@@ -218,8 +218,13 @@ public class TarInputStream extends FilterInputStream {
                         + numToSkip + " bytes");
             }
 
-            if (numToSkip > 0) {
-                skip(numToSkip);
+            while (numToSkip > 0) {
+                long skipped = skip(numToSkip);
+                if (skipped <= 0) {
+                    throw new RuntimeException("failed to skip current tar"
+                                               + " entry");
+                }
+                numToSkip -= skipped;
             }
 
             readBuf = null;
diff --git a/src/main/org/apache/tools/tar/TarOutputStream.java b/src/main/org/apache/tools/tar/TarOutputStream.java
index 50fa2c186..417ad28e2 100644
--- a/src/main/org/apache/tools/tar/TarOutputStream.java
+++ b/src/main/org/apache/tools/tar/TarOutputStream.java
@@ -310,7 +310,7 @@ public class TarOutputStream extends FilterOutputStream {
 
                 wOffset += numToWrite;
                 assemLen += numToWrite;
-                numToWrite -= numToWrite;
+                numToWrite = 0;
             }
         }
 
diff --git a/src/main/org/apache/tools/zip/AsiExtraField.java b/src/main/org/apache/tools/zip/AsiExtraField.java
index a5ce0a5a6..a9634dc43 100644
--- a/src/main/org/apache/tools/zip/AsiExtraField.java
+++ b/src/main/org/apache/tools/zip/AsiExtraField.java
@@ -334,4 +334,14 @@ public class AsiExtraField implements ZipExtraField, UnixStat, Cloneable {
         return type | (mode & PERM_MASK);
     }
 
+    public Object clone() {
+        try {
+            AsiExtraField cloned = (AsiExtraField) super.clone();
+            cloned.crc = new CRC32();
+            return cloned;
+        } catch (CloneNotSupportedException cnfe) {
+            // impossible
+            throw new RuntimeException(cnfe);
+        }
+    }
 }
diff --git a/src/main/org/apache/tools/zip/UnrecognizedExtraField.java b/src/main/org/apache/tools/zip/UnrecognizedExtraField.java
index 79f2e6e1b..6c59f8700 100644
--- a/src/main/org/apache/tools/zip/UnrecognizedExtraField.java
+++ b/src/main/org/apache/tools/zip/UnrecognizedExtraField.java
@@ -65,7 +65,7 @@ public class UnrecognizedExtraField implements ZipExtraField {
      * @param data the field data to use
      */
     public void setLocalFileDataData(byte[] data) {
-        localData = data;
+        localData = copy(data);
     }
 
     /**
@@ -81,7 +81,7 @@ public class UnrecognizedExtraField implements ZipExtraField {
      * @return the local data
      */
     public byte[] getLocalFileDataData() {
-        return localData;
+        return copy(localData);
     }
 
     /**
@@ -97,7 +97,7 @@ public class UnrecognizedExtraField implements ZipExtraField {
      * @param data the data to use
      */
     public void setCentralDirectoryData(byte[] data) {
-        centralData = data;
+        centralData = copy(data);
     }
 
     /**
@@ -118,7 +118,7 @@ public class UnrecognizedExtraField implements ZipExtraField {
      */
     public byte[] getCentralDirectoryData() {
         if (centralData != null) {
-            return centralData;
+            return copy(centralData);
         }
         return getLocalFileDataData();
     }
@@ -134,4 +134,13 @@ public class UnrecognizedExtraField implements ZipExtraField {
         System.arraycopy(data, offset, tmp, 0, length);
         setLocalFileDataData(tmp);
     }
+
+    private static byte[] copy(byte[] from) {
+        if (from != null) {
+            byte[] to = new byte[from.length];
+            System.arraycopy(from, 0, to, 0, to.length);
+            return to;
+        }
+        return null;
+    }
 }
diff --git a/src/main/org/apache/tools/zip/ZipFile.java b/src/main/org/apache/tools/zip/ZipFile.java
index 6a85f770a..d59e8fa93 100644
--- a/src/main/org/apache/tools/zip/ZipFile.java
+++ b/src/main/org/apache/tools/zip/ZipFile.java
@@ -345,7 +345,15 @@ public class ZipFile {
 
             nameMap.put(ze.getName(), ze);
 
-            archive.skipBytes(extraLen);
+            int lenToSkip = extraLen;
+            while (lenToSkip > 0) {
+                int skipped = archive.skipBytes(lenToSkip);
+                if (skipped <= 0) {
+                    throw new RuntimeException("failed to skip extra data in"
+                                               + " central directory");
+                }
+                lenToSkip -= skipped;
+            }            
 
             byte[] comment = new byte[commentLen];
             archive.readFully(comment);
@@ -461,7 +469,15 @@ public class ZipFile {
             int fileNameLen = ZipShort.getValue(b);
             archive.readFully(b);
             int extraFieldLen = ZipShort.getValue(b);
-            archive.skipBytes(fileNameLen);
+            int lenToSkip = fileNameLen;
+            while (lenToSkip > 0) {
+                int skipped = archive.skipBytes(lenToSkip);
+                if (skipped <= 0) {
+                    throw new RuntimeException("failed to skip file name in"
+                                               + " local file header");
+                }
+                lenToSkip -= skipped;
+            }            
             byte[] localExtraData = new byte[extraFieldLen];
             archive.readFully(localExtraData);
             ze.setExtra(localExtraData);
diff --git a/src/main/org/apache/tools/zip/ZipLong.java b/src/main/org/apache/tools/zip/ZipLong.java
index 677f95480..a6b5dda39 100644
--- a/src/main/org/apache/tools/zip/ZipLong.java
+++ b/src/main/org/apache/tools/zip/ZipLong.java
@@ -147,4 +147,13 @@ public final class ZipLong implements Cloneable {
     public int hashCode() {
         return (int) value;
     }
+
+    public Object clone() {
+        try {
+            return (ZipLong) super.clone();
+        } catch (CloneNotSupportedException cnfe) {
+            // impossible
+            throw new RuntimeException(cnfe);
+        }
+    }
 }
diff --git a/src/main/org/apache/tools/zip/ZipShort.java b/src/main/org/apache/tools/zip/ZipShort.java
index d75634932..da6ca490a 100644
--- a/src/main/org/apache/tools/zip/ZipShort.java
+++ b/src/main/org/apache/tools/zip/ZipShort.java
@@ -133,4 +133,13 @@ public final class ZipShort implements Cloneable {
     public int hashCode() {
         return value;
     }
+
+    public Object clone() {
+        try {
+            return (ZipShort) super.clone();
+        } catch (CloneNotSupportedException cnfe) {
+            // impossible
+            throw new RuntimeException(cnfe);
+        }
+    }
 }
diff --git a/src/tests/junit/org/apache/tools/zip/AsiExtraFieldTest.java b/src/tests/junit/org/apache/tools/zip/AsiExtraFieldTest.java
index c8e4fe418..fbfe06c94 100644
--- a/src/tests/junit/org/apache/tools/zip/AsiExtraFieldTest.java
+++ b/src/tests/junit/org/apache/tools/zip/AsiExtraFieldTest.java
@@ -138,4 +138,20 @@ public class AsiExtraFieldTest extends TestCase implements UnixStat {
                          e.getMessage());
         }
     }
+
+    public void testClone() {
+        AsiExtraField s1 = new AsiExtraField();
+        s1.setUserId(42);
+        s1.setGroupId(12);
+        s1.setLinkedFile("foo");
+        s1.setMode(0644);
+        s1.setDirectory(true);
+        AsiExtraField s2 = (AsiExtraField) s1.clone();
+        assertNotSame(s1, s2);
+        assertEquals(s1.getUserId(), s2.getUserId());
+        assertEquals(s1.getGroupId(), s2.getGroupId());
+        assertEquals(s1.getLinkedFile(), s2.getLinkedFile());
+        assertEquals(s1.getMode(), s2.getMode());
+        assertEquals(s1.isDirectory(), s2.isDirectory());
+    }
 }
diff --git a/src/tests/junit/org/apache/tools/zip/ZipLongTest.java b/src/tests/junit/org/apache/tools/zip/ZipLongTest.java
index e72aaaaef..1b729900d 100644
--- a/src/tests/junit/org/apache/tools/zip/ZipLongTest.java
+++ b/src/tests/junit/org/apache/tools/zip/ZipLongTest.java
@@ -79,4 +79,11 @@ public class ZipLongTest extends TestCase {
         assertEquals(0x00000000FFFFFFFFl, zl.getValue());
     }
 
+    public void testClone() {
+        ZipLong s1 = new ZipLong(42);
+        ZipLong s2 = (ZipLong) s1.clone();
+        assertNotSame(s1, s2);
+        assertEquals(s1, s2);
+        assertEquals(s1.getValue(), s2.getValue());
+    }
 }
diff --git a/src/tests/junit/org/apache/tools/zip/ZipShortTest.java b/src/tests/junit/org/apache/tools/zip/ZipShortTest.java
index 3fb604f7d..aff065dfc 100644
--- a/src/tests/junit/org/apache/tools/zip/ZipShortTest.java
+++ b/src/tests/junit/org/apache/tools/zip/ZipShortTest.java
@@ -77,4 +77,11 @@ public class ZipShortTest extends TestCase {
         assertEquals(0x0000FFFF, zs.getValue());
     }
 
+    public void testClone() {
+        ZipShort s1 = new ZipShort(42);
+        ZipShort s2 = (ZipShort) s1.clone();
+        assertNotSame(s1, s2);
+        assertEquals(s1, s2);
+        assertEquals(s1.getValue(), s2.getValue());
+    }
 }