# HG changeset patch
# User Joerg Sonnenberger <joerg@bec.de>
# Date 2018-08-16 03:50:49
# Node ID 1af95139e5ecf70ddf585776774e4531cf340838
# Parent  362c4603602dc504c174862ce3bedde6e786a302

util: improve handling of truncated compressed streams

If the compressed stream is over as marked by the reader providing
nothing new and the compression engine is not providing data, bail out.
This can happen in practise when the server misbehaves and would result
in an infinite loop otherwise.

Differential Revision: https://phab.mercurial-scm.org/D4297

diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -3377,6 +3377,9 @@ class _CompressedStreamReader(object):
                 return ''.join(buf)
             chunk = self._reader(65536)
             self._decompress(chunk)
+            if not chunk and not self._pending and not self._eof:
+                # No progress and no new data, bail out
+                return ''.join(buf)
 
 class _GzipCompressedStreamReader(_CompressedStreamReader):
     def __init__(self, fh):