From 2f38faea5c259ec1d8f381000f437db83a747898 Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Wed, 12 Apr 2017 16:03:23 +0300
Subject: [PATCH] bpo-30017: Allowed calling the close() method of the zip
 entry writer object (#1041) multiple times.  Writing to closed zip entry
 writer object now always produce a ValueError. (cherry picked from commit
 4c0d9ea995da595e90e08813b89510de59907802)

---
 Lib/test/test_zipfile.py | 42 ++++++++++++++++++++++++++++++++++++++++
 Lib/zipfile.py           |  4 ++++
 Misc/NEWS                |  3 +++
 3 files changed, 49 insertions(+)

diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index d39f05fdb7788e..d09ad96fc8baaa 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -734,6 +734,48 @@ class LzmaTestZip64InSmallFiles(AbstractTestZip64InSmallFiles,
     compression = zipfile.ZIP_LZMA
 
 
+class AbstractWriterTests:
+
+    def tearDown(self):
+        unlink(TESTFN2)
+
+    def test_close_after_close(self):
+        data = b'content'
+        with zipfile.ZipFile(TESTFN2, "w", self.compression) as zipf:
+            w = zipf.open('test', 'w')
+            w.write(data)
+            w.close()
+            self.assertTrue(w.closed)
+            w.close()
+            self.assertTrue(w.closed)
+            self.assertEqual(zipf.read('test'), data)
+
+    def test_write_after_close(self):
+        data = b'content'
+        with zipfile.ZipFile(TESTFN2, "w", self.compression) as zipf:
+            w = zipf.open('test', 'w')
+            w.write(data)
+            w.close()
+            self.assertTrue(w.closed)
+            self.assertRaises(ValueError, w.write, b'')
+            self.assertEqual(zipf.read('test'), data)
+
+class StoredWriterTests(AbstractWriterTests, unittest.TestCase):
+    compression = zipfile.ZIP_STORED
+
+@requires_zlib
+class DeflateWriterTests(AbstractWriterTests, unittest.TestCase):
+    compression = zipfile.ZIP_DEFLATED
+
+@requires_bz2
+class Bzip2WriterTests(AbstractWriterTests, unittest.TestCase):
+    compression = zipfile.ZIP_BZIP2
+
+@requires_lzma
+class LzmaWriterTests(AbstractWriterTests, unittest.TestCase):
+    compression = zipfile.ZIP_LZMA
+
+
 class PyZipFileTests(unittest.TestCase):
     def assertCompiledIn(self, name, namelist):
         if name + 'o' not in namelist:
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index d7f5beba996e6e..06eedec340bc17 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -981,6 +981,8 @@ def writable(self):
         return True
 
     def write(self, data):
+        if self.closed:
+            raise ValueError('I/O operation on closed file.')
         nbytes = len(data)
         self._file_size += nbytes
         self._crc = crc32(data, self._crc)
@@ -991,6 +993,8 @@ def write(self, data):
         return nbytes
 
     def close(self):
+        if self.closed:
+            return
         super().close()
         # Flush any data from the compressor, and update header info
         if self._compressor:
diff --git a/Misc/NEWS b/Misc/NEWS
index 83f9e7a6852560..448efc9f3a5528 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -32,6 +32,9 @@ Core and Builtins
 Library
 -------
 
+- bpo-30017: Allowed calling the close() method of the zip entry writer object
+  multiple times.  Writing to a closed writer now always produces a ValueError.
+
 - bpo-29998: Pickling and copying ImportError now preserves name and path
   attributes.