[Python-checkins] Revert "bpo-35603: Escape table header of make_table output that can cause potential XSS. (GH-11341)" (GH-11356)

[Serhiy Storchaka]

https://github.com/python/cpython/commit/830ddc74c495ac1a5c03172a31006074967571a3
commit: 830ddc74c495ac1a5c03172a31006074967571a3
branch: master
author: Serhiy Storchaka <storchaka at gmail.com>
committer: GitHub <noreply at github.com>
date: 2019-01-02T14:49:25+02:00
summary:

Revert "bpo-35603: Escape table header of make_table output that can cause potential XSS. (GH-11341)" (GH-11356)

This reverts commit 78de01198b047347abc5e458851bb12c48429e24.

files:
D Misc/NEWS.d/next/Library/2018-12-28-14-53-22.bpo-35603.rVCZAE.rst
M Lib/difflib.py
M Lib/test/test_difflib.py

diff --git a/Lib/difflib.py b/Lib/difflib.py
index 4571817b9823..887c3c26cae4 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -2036,10 +2036,6 @@ def make_table(self,fromlines,tolines,fromdesc='',todesc='',context=False,
                 s.append( fmt % (next_id[i],next_href[i],fromlist[i],
                                            next_href[i],tolist[i]))
         if fromdesc or todesc:
-            fromdesc = fromdesc.replace("&", "&").replace(">", ">") \
-                                                     .replace("<", "<")
-            todesc = todesc.replace("&", "&").replace(">", ">") \
-                                                 .replace("<", "<")
             header_row = '<thead><tr>%s%s%s%s</tr></thead>' % (
                 '<th class="diff_next"><br /></th>',
                 '<th colspan="2" class="diff_header">%s</th>' % fromdesc,
diff --git a/Lib/test/test_difflib.py b/Lib/test/test_difflib.py
index 63ebdb0dc83b..745ccbd6659e 100644
--- a/Lib/test/test_difflib.py
+++ b/Lib/test/test_difflib.py
@@ -238,15 +238,6 @@ def test_html_diff(self):
         with open(findfile('test_difflib_expect.html')) as fp:
             self.assertEqual(actual, fp.read())
 
-    def test_make_table_escape_table_header(self):
-        html_diff = difflib.HtmlDiff()
-        output = html_diff.make_table(patch914575_from1.splitlines(),
-                                      patch914575_to1.splitlines(),
-                                      fromdesc='<from>',
-                                      todesc='<to>')
-        self.assertIn('<from>', output)
-        self.assertIn('<to>', output)
-
     def test_recursion_limit(self):
         # Check if the problem described in patch #1413711 exists.
         limit = sys.getrecursionlimit()
diff --git a/Misc/NEWS.d/next/Library/2018-12-28-14-53-22.bpo-35603.rVCZAE.rst b/Misc/NEWS.d/next/Library/2018-12-28-14-53-22.bpo-35603.rVCZAE.rst
deleted file mode 100644
index 03150c3aa494..000000000000
--- a/Misc/NEWS.d/next/Library/2018-12-28-14-53-22.bpo-35603.rVCZAE.rst
+++ /dev/null
@@ -1,2 +0,0 @@
-Escape table header output of :meth:`difflib.HtmlDiff.make_table`.
-Patch by Karthikeyan Singaravelan.