Merged revisions 85455 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r85455 | georg.brandl | 2010-10-14 08:59:45 +0200 (Do, 14 Okt 2010) | 1 line

  #1710703: write zipfile structures also in the case of closing a new, but empty, archive.
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diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index aee499c..ddd713f 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -949,6 +949,31 @@
     def test_read_return_size_deflated(self):
         self.check_read_return_size(zipfile.ZIP_DEFLATED)
 
+    def test_empty_zipfile(self):
+        # Check that creating a file in 'w' or 'a' mode and closing without
+        # adding any files to the archives creates a valid empty ZIP file
+        zipf = zipfile.ZipFile(TESTFN, mode="w")
+        zipf.close()
+        try:
+            zipf = zipfile.ZipFile(TESTFN, mode="r")
+        except zipfile.BadZipFile:
+            self.fail("Unable to create empty ZIP file in 'w' mode")
+
+        zipf = zipfile.ZipFile(TESTFN, mode="a")
+        zipf.close()
+        try:
+            zipf = zipfile.ZipFile(TESTFN, mode="r")
+        except:
+            self.fail("Unable to create empty ZIP file in 'a' mode")
+
+    def test_open_empty_file(self):
+        # Issue 1710703: Check that opening a file with less than 22 bytes
+        # raises a BadZipfile exception (rather than the previously unhelpful
+        # IOError)
+        f = open(TESTFN, 'w')
+        f.close()
+        self.assertRaises(zipfile.BadZipfile, zipfile.ZipFile, TESTFN, 'r')
+
     def tearDown(self):
         unlink(TESTFN)
         unlink(TESTFN2)