[Python-checkins] bpo-34791: xml package obeys ignore env flags (GH-9544) (GH-9547)

[Victor Stinner]

https://github.com/python/cpython/commit/2546ac8eeb56fc146adea9a03158440a9271714e
commit: 2546ac8eeb56fc146adea9a03158440a9271714e
branch: 2.7
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: Victor Stinner <vstinner at redhat.com>
date: 2018-10-20T01:09:35+02:00
summary:

bpo-34791: xml package obeys ignore env flags (GH-9544) (GH-9547)

The xml.sax and xml.dom.domreg modules now obey
sys.flags.ignore_environment.

Signed-off-by: Christian Heimes <christian at python.org>

https://bugs.python.org/issue34791
(cherry picked from commit 223e501fb9c2b6ae21b96054e20c4c31d94a5d96)

Co-authored-by: Christian Heimes <christian at python.org>

files:
A Misc/NEWS.d/next/Security/2018-09-24-18-49-25.bpo-34791.78GmIG.rst
M Lib/xml/dom/domreg.py
M Lib/xml/sax/__init__.py

diff --git a/Lib/xml/dom/domreg.py b/Lib/xml/dom/domreg.py
index ec3acdf9c1dd..083528010663 100644
--- a/Lib/xml/dom/domreg.py
+++ b/Lib/xml/dom/domreg.py
@@ -8,6 +8,8 @@
 # should be published by posting to xml-sig at python.org, and are
 # subsequently recorded in this file.
 
+import sys
+
 well_known_implementations = {
     'minidom':'xml.dom.minidom',
     '4DOM': 'xml.dom.DOMImplementation',
@@ -57,7 +59,7 @@ def getDOMImplementation(name = None, features = ()):
         return mod.getDOMImplementation()
     elif name:
         return registered[name]()
-    elif "PYTHON_DOM" in os.environ:
+    elif not sys.flags.ignore_environment and "PYTHON_DOM" in os.environ:
         return getDOMImplementation(name = os.environ["PYTHON_DOM"])
 
     # User did not specify a name, try implementations in arbitrary
diff --git a/Lib/xml/sax/__init__.py b/Lib/xml/sax/__init__.py
index 005b66e38a8e..d2e33913c075 100644
--- a/Lib/xml/sax/__init__.py
+++ b/Lib/xml/sax/__init__.py
@@ -59,7 +59,7 @@ def parseString(string, handler, errorHandler=ErrorHandler()):
     import xml.sax.expatreader
 
 import os, sys
-if "PY_SAX_PARSER" in os.environ:
+if not sys.flags.ignore_environment and "PY_SAX_PARSER" in os.environ:
     default_parser_list = os.environ["PY_SAX_PARSER"].split(",")
 del os
 
diff --git a/Misc/NEWS.d/next/Security/2018-09-24-18-49-25.bpo-34791.78GmIG.rst b/Misc/NEWS.d/next/Security/2018-09-24-18-49-25.bpo-34791.78GmIG.rst
new file mode 100644
index 000000000000..afb59f8cb0eb
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2018-09-24-18-49-25.bpo-34791.78GmIG.rst
@@ -0,0 +1,3 @@
+The xml.sax and xml.dom.domreg no longer use environment variables to
+override parser implementations when sys.flags.ignore_environment is set by
+-E or -I arguments.