[Python-checkins] cpython (2.7): Issue #20048: Fixed ZipExtFile.peek() when it is called on the boundary of

[serhiy.storchaka]

http://hg.python.org/cpython/rev/8b097d07488d
changeset:   88117:8b097d07488d
branch:      2.7
parent:      88084:81f8375e60ce
user:        Serhiy Storchaka <storchaka at gmail.com>
date:        Sat Dec 21 23:51:15 2013 +0200
summary:
  Issue #20048: Fixed ZipExtFile.peek() when it is called on the boundary of
the uncompress buffer and read() goes through more than one readbuffer.

This is partial backport of changeset 028e8e0b03e8.

files:
  Lib/zipfile.py |  6 +++++-
  Misc/NEWS      |  3 +++
  2 files changed, 8 insertions(+), 1 deletions(-)


diff --git a/Lib/zipfile.py b/Lib/zipfile.py
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -606,7 +606,11 @@
         """Returns buffered bytes without advancing the position."""
         if n > len(self._readbuffer) - self._offset:
             chunk = self.read(n)
-            self._offset -= len(chunk)
+            if len(chunk) > self._offset:
+                self._readbuffer = chunk + self._readbuffer[self._offset:]
+                self._offset = 0
+            else:
+                self._offset -= len(chunk)
 
         # Return up to 512 bytes to reduce allocation overhead for tight loops.
         return self._readbuffer[self._offset: self._offset + 512]
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -27,6 +27,9 @@
 Library
 -------
 
+- Issue #20048: Fixed ZipExtFile.peek() when it is called on the boundary of
+  the uncompress buffer and read() goes through more than one readbuffer.
+
 - Issue #20034: Updated alias mapping to most recent locale.alias file
   from X.org distribution using makelocalealias.py.
 

-- 
Repository URL: http://hg.python.org/cpython