Issue #2846: Add support for gzip.GzipFile reading zero-padded files.

Patch by Brian Curtin.

1 files changed, 9 insertions, 0 deletions

diff --git a/Lib/gzip.py b/Lib/gzip.py
index 26f4354..13f2ca2 100644
--- a/Lib/gzip.py
+++ b/Lib/gzip.py
@@ -330,6 +330,15 @@ class GzipFile(io.BufferedIOBase):
         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