1 files changed, 39 insertions, 3 deletions
diff --git a/bs4/testing.py b/bs4/testing.py
index a2f83a1..87cd13f 100644
--- a/bs4/testing.py
+++ b/bs4/testing.py
@@ -8,6 +8,7 @@ import pickle
 import copy
 import functools
 import unittest
+import warnings
 from unittest import TestCase
 from bs4 import BeautifulSoup
 from bs4.element import (
@@ -228,7 +229,42 @@ class SoupTest(unittest.TestCase):
             return child
 
 
-class HTMLTreeBuilderSmokeTest(object):
+class TreeBuilderSmokeTest(object):
+    # Tests that are common to HTML and XML tree builders.
+
+    def test_fuzzed_input(self):
+        # This test centralizes in one place the various fuzz tests
+        # for Beautiful Soup created by the oss-fuzz.
+        
+        # These strings superficially resemble markup, but they
+        # generally can't be parsed into anything. The best we can
+        # hope for is that parsing these strings won't crash the
+        # parser.
+
+        # n.b. This markup is commented out because these fuzz tests
+        # _do_ crash the parser. However the crashes are due to bugs
+        # in html.parser, not Beautiful Soup -- otherwise I'd fix the
+        # bugs!
+        
+        bad_markup = [
+            # https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28873
+            # https://github.com/guidovranken/python-library-fuzzers/blob/master/corp-html/519e5b4269a01185a0d5e76295251921da2f0700
+            # https://bugs.python.org/issue37747
+            #
+            #b'\n<![\xff\xfe\xfe\xcd\x00',
+
+            #https://github.com/guidovranken/python-library-fuzzers/blob/master/corp-html/de32aa55785be29bbc72a1a8e06b00611fb3d9f8
+            # https://bugs.python.org/issue34480
+            #
+            #b'<![n\x00'
+        ]
+        for markup in bad_markup:
+            with warnings.catch_warnings(record=False):
+                soup = self.soup(markup)
+                pass
+        
+
+class HTMLTreeBuilderSmokeTest(TreeBuilderSmokeTest):
 
     """A basic test of a treebuilder's competence.
 
@@ -651,7 +687,7 @@ Hello, world!
         markup = b'<a class="foo bar">'
         soup = self.soup(markup)
         self.assertEqual(['foo', 'bar'], soup.a['class'])
-
+        
     #
     # Generally speaking, tests below this point are more tests of
     # Beautiful Soup than tests of the tree builders. But parsers are
@@ -881,7 +917,7 @@ Hello, world!
         self.linkage_validator(soup)
 
 
-class XMLTreeBuilderSmokeTest(object):
+class XMLTreeBuilderSmokeTest(TreeBuilderSmokeTest):
 
     def test_pickle_and_unpickle_identity(self):
         # Pickling a tree, then unpickling it, yields a tree identical