[Python-checkins] r77472 - in python/trunk: Doc/library/gzip.rst Lib/gzip.py Lib/test/test_gzip.py Misc/NEWS

[antoine.pitrou]

Author: antoine.pitrou
Date: Wed Jan 13 15:32:10 2010
New Revision: 77472

Log:
Issue #2846: Add support for gzip.GzipFile reading zero-padded files.
Patch by Brian Curtin.




Modified:
   python/trunk/Doc/library/gzip.rst
   python/trunk/Lib/gzip.py
   python/trunk/Lib/test/test_gzip.py
   python/trunk/Misc/NEWS

Modified: python/trunk/Doc/library/gzip.rst
==============================================================================
--- python/trunk/Doc/library/gzip.rst	(original)
+++ python/trunk/Doc/library/gzip.rst	Wed Jan 13 15:32:10 2010
@@ -72,6 +72,9 @@
    .. versionchanged:: 2.7
       Support for the :keyword:`with` statement was added.
 
+   .. versionchanged:: 2.7
+      Support for zero-padded files was added.
+
 
 .. function:: open(filename[, mode[, compresslevel]])
 

Modified: python/trunk/Lib/gzip.py
==============================================================================
--- python/trunk/Lib/gzip.py	(original)
+++ python/trunk/Lib/gzip.py	Wed Jan 13 15:32:10 2010
@@ -330,6 +330,15 @@
         elif isize != (self.size & 0xffffffffL):
             raise IOError, "Incorrect length of data produced"
 
+        # Gzip files can be padded with zeroes and still have archives.
+        # Consume all zero bytes and set the file position to the first
+        # non-zero byte. See http://www.gzip.org/#faq8
+        c = "\x00"
+        while c == "\x00":
+            c = self.fileobj.read(1)
+        if c:
+            self.fileobj.seek(-1, 1)
+
     @property
     def closed(self):
         return self.fileobj is None

Modified: python/trunk/Lib/test/test_gzip.py
==============================================================================
--- python/trunk/Lib/test/test_gzip.py	(original)
+++ python/trunk/Lib/test/test_gzip.py	Wed Jan 13 15:32:10 2010
@@ -252,6 +252,18 @@
         else:
             self.fail("1/0 didn't raise an exception")
 
+    def test_zero_padded_file(self):
+        with gzip.GzipFile(self.filename, "wb") as f:
+            f.write(data1 * 50)
+
+        # Pad the file with zeroes
+        with open(self.filename, "ab") as f:
+            f.write("\x00" * 50)
+
+        with gzip.GzipFile(self.filename, "rb") as f:
+            d = f.read()
+            self.assertEqual(d, data1 * 50, "Incorrect data in file")
+
 def test_main(verbose=None):
     test_support.run_unittest(TestGzip)
 

Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS	(original)
+++ python/trunk/Misc/NEWS	Wed Jan 13 15:32:10 2010
@@ -32,6 +32,9 @@
 Library
 -------
 
+- Issue #2846: Add support for gzip.GzipFile reading zero-padded files.
+  Patch by Brian Curtin.
+
 - Issue #5827: Make sure that normpath preserves unicode.  Initial patch
   by Matt Giuca.