diff -r 358a35471f9f Lib/tarfile.py
--- a/Lib/tarfile.py	Fri Dec 13 20:53:26 2013 -0500
+++ b/Lib/tarfile.py	Sat Dec 14 17:18:46 2013 +0800
@@ -1996,8 +1996,12 @@
             tarinfo._link_target = os.path.join(path, tarinfo.linkname)
 
         try:
-            self._extract_member(tarinfo, os.path.join(path, tarinfo.name),
-                                 set_attrs=set_attrs)
+            joined_path = '/' + tarinfo.name
+            # We don't want to join '/home/user' and 'home/user/file' to avoid
+            # '/home/user/home/user/file'.
+            if path != joined_path[:len(path)]:
+                joined_path = os.path.join(path, tarinfo.name)
+            self._extract_member(tarinfo, joined_path, set_attrs=set_attrs)
         except OSError as e:
             if self.errorlevel > 0:
                 raise
@@ -2155,6 +2159,8 @@
         try:
             # For systems that support symbolic and hard links.
             if tarinfo.issym():
+                if os.path.exists(targetpath):
+                    os.unlink(targetpath)
                 os.symlink(tarinfo.linkname, targetpath)
             else:
                 # See extract().
diff -r 358a35471f9f Lib/test/test_tarfile.py
--- a/Lib/test/test_tarfile.py	Fri Dec 13 20:53:26 2013 -0500
+++ b/Lib/test/test_tarfile.py	Sat Dec 14 17:18:46 2013 +0800
@@ -1068,20 +1068,28 @@
         temparchive = os.path.join(TEMPDIR, "testsymlinks.tar")
         os.mkdir(tempdir)
         try:
-            source_file = os.path.join(tempdir,'source')
+            source_file = os.path.join(tempdir, 'source')
+            other_source_file = os.path.join(tempdir, 'other_source')
             target_file = os.path.join(tempdir,'symlink')
-            with open(source_file,'w') as f:
-                f.write('something\n')
+            open(source_file, 'w').close()
+            open(other_source_file, 'w').close()
             os.symlink(source_file, target_file)
             tar = tarfile.open(temparchive,'w')
             tar.add(source_file)
             tar.add(target_file)
             tar.close()
+            # Point target_file to other_source_file to exersice overwriting
+            # behavior.
+            os.unlink(target_file)
+            os.symlink(other_source_file, target_file)
             # Let's extract it to the location which contains the symlink
             tar = tarfile.open(temparchive,'r')
-            # this should not raise OSError: [Errno 17] File exists
+            # This should not raise OSError: [Errno 17] File exists
             try:
                 tar.extractall(path=tempdir)
+                # target_file that symlinked to other_source_file now symlinks
+                # back to source_file.
+                self.assertEqual(os.readlink(target_file), source_file)
             except OSError:
                 self.fail("extractall failed with symlinked files")
             finally: