Index: Lib/zipfile.py
===================================================================
--- Lib/zipfile.py	(version 67911)
+++ Lib/zipfile.py	(working copy)
@@ -945,9 +945,14 @@
         """
         # build the destination pathname, replacing
         # forward slashes to platform specific separators.
-        if targetpath[-1:] == "/":
+        if targetpath[-1:] == os.sep:
             targetpath = targetpath[:-1]
 
+        isdir = False
+
+        if member.filename[-1:] == os.sep:
+            isdir = True
+
         # don't include leading "/" from file name if present
         if os.path.isabs(member.filename):
             targetpath = os.path.join(targetpath, member.filename[1:])
@@ -958,9 +963,13 @@
 
         # Create all upper directories if necessary.
         upperdirs = os.path.dirname(targetpath)
-        if upperdirs and not os.path.exists(upperdirs):
+        if upperdirs and not os.path.isdir(upperdirs):
             os.makedirs(upperdirs)
 
+        if isdir:
+            os.mkdir(targetpath)
+            return targetpath
+
         source = self.open(member, pwd=pwd)
         target = file(targetpath, "wb")
         shutil.copyfileobj(source, target)
@@ -999,15 +1008,26 @@
             raise RuntimeError(
                   "Attempt to write to ZIP archive that was already closed")
 
+        isdir = False
+
+        if os.path.isdir(filename):
+            isdir = True
+
         st = os.stat(filename)
         mtime = time.localtime(st.st_mtime)
         date_time = mtime[0:6]
+
         # Create ZipInfo instance to store file information
         if arcname is None:
             arcname = filename
+
         arcname = os.path.normpath(os.path.splitdrive(arcname)[1])
         while arcname[0] in (os.sep, os.altsep):
             arcname = arcname[1:]
+
+        if isdir:
+            arcname += os.sep
+
         zinfo = ZipInfo(arcname, date_time)
         zinfo.external_attr = (st[0] & 0xFFFF) << 16L      # Unix attributes
         if compress_type is None:
@@ -1019,6 +1039,14 @@
         zinfo.flag_bits = 0x00
         zinfo.header_offset = self.fp.tell()    # Start of header bytes
 
+        if isdir:
+            zinfo.file_size = 0
+            zinfo.compress_size = 0
+            zinfo.CRC = 0
+            self.filelist.append(zinfo)
+            self.NameToInfo[zinfo.filename] = zinfo
+            return
+
         self._writecheck(zinfo)
         self._didModify = True
         fp = open(filename, "rb")