[Python-checkins] cpython (3.2): #15546: Fix GzipFile.peek()'s handling of pathological input data.

[serhiy.storchaka]

http://hg.python.org/cpython/rev/0f25119ceee8
changeset:   81651:0f25119ceee8
branch:      3.2
parent:      81648:1ff413ba4414
user:        Serhiy Storchaka <storchaka at gmail.com>
date:        Tue Jan 22 15:54:48 2013 +0200
summary:
  #15546: Fix GzipFile.peek()'s handling of pathological input data.
This is a backport of changeset 8c07ff7f882f.

files:
  Lib/gzip.py |  6 ++++--
  Misc/NEWS   |  3 +++
  2 files changed, 7 insertions(+), 2 deletions(-)


diff --git a/Lib/gzip.py b/Lib/gzip.py
--- a/Lib/gzip.py
+++ b/Lib/gzip.py
@@ -367,8 +367,10 @@
             if self.fileobj is None:
                 return b''
             try:
-                # 1024 is the same buffering heuristic used in read()
-                self._read(max(n, 1024))
+                # Ensure that we don't return b"" if we haven't reached EOF.
+                while self.extrasize == 0:
+                    # 1024 is the same buffering heuristic used in read()
+                    self._read(max(n, 1024))
             except EOFError:
                 pass
         offset = self.offset - self.extrastart
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -466,6 +466,9 @@
 - Issue #15424: Add a __sizeof__ implementation for array objects.
   Patch by Ludwig Hähne.
 
+- Issue #15546: Fix handling of pathological input data in the peek() method
+  of the GzipFile class.
+
 - Issue #13052: Fix IDLE crashing when replace string in Search/Replace dialog
   ended with '\'. Patch by Roger Serwy.
 

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