Remove six dependency from html5lib (#618)

This way lies madness, but at least we don't have a six dependency
anymore.

The way this work is that we vendored html5lib 1.1, but then this
applies a 01_html5lib_six.patch to that which changes imports from six
to import from bleach.six_shim.

This updates the vendor management code and vendorverify to install
html5lib 1.1 and then apply the patch and then compare with what's in
the tree. If we end up applying further patches in the future, we can
use this model to do that.

bleach/_vendor/01_html5lib_six.patch

@@ -0,0 +1,158 @@
+diff --git bleach/_vendor/html5lib/_inputstream.py bleach/_vendor/html5lib/_inputstream.py
+index 0207dd2..0976251 100644
+--- bleach/_vendor/html5lib/_inputstream.py
++++ bleach/_vendor/html5lib/_inputstream.py
+@@ -1,7 +1,7 @@
+ from __future__ import absolute_import, division, unicode_literals
+
+-from six import text_type
+-from six.moves import http_client, urllib
++from bleach.six_shim import text_type
++from bleach.six_shim import http_client, urllib
+
+ import codecs
+ import re
+diff --git bleach/_vendor/html5lib/_tokenizer.py bleach/_vendor/html5lib/_tokenizer.py
+index 4748a19..d884801 100644
+--- bleach/_vendor/html5lib/_tokenizer.py
++++ bleach/_vendor/html5lib/_tokenizer.py
+@@ -1,6 +1,6 @@
+ from __future__ import absolute_import, division, unicode_literals
+
+-from six import unichr as chr
++from bleach.six_shim import unichr as chr
+
+ from collections import deque, OrderedDict
+ from sys import version_info
+diff --git bleach/_vendor/html5lib/_trie/py.py bleach/_vendor/html5lib/_trie/py.py
+index c2ba3da..56f66bd 100644
+--- bleach/_vendor/html5lib/_trie/py.py
++++ bleach/_vendor/html5lib/_trie/py.py
+@@ -1,5 +1,5 @@
+ from __future__ import absolute_import, division, unicode_literals
+-from six import text_type
++from bleach.six_shim import text_type
+
+ from bisect import bisect_left
+
+diff --git bleach/_vendor/html5lib/_utils.py bleach/_vendor/html5lib/_utils.py
+index 9ea5794..635bb02 100644
+--- bleach/_vendor/html5lib/_utils.py
++++ bleach/_vendor/html5lib/_utils.py
+@@ -7,7 +7,7 @@ try:
+ except ImportError:
+     from collections import Mapping
+
+-from six import text_type, PY3
++from bleach.six_shim import text_type, PY3
+
+ if PY3:
+     import xml.etree.ElementTree as default_etree
+diff --git bleach/_vendor/html5lib/filters/lint.py bleach/_vendor/html5lib/filters/lint.py
+index acd4d7a..1340d97 100644
+--- bleach/_vendor/html5lib/filters/lint.py
++++ bleach/_vendor/html5lib/filters/lint.py
+@@ -1,6 +1,6 @@
+ from __future__ import absolute_import, division, unicode_literals
+
+-from six import text_type
++from bleach.six_shim import text_type
+
+ from . import base
+ from ..constants import namespaces, voidElements
+diff --git bleach/_vendor/html5lib/filters/sanitizer.py bleach/_vendor/html5lib/filters/sanitizer.py
+index 70ef906..5c31e97 100644
+--- bleach/_vendor/html5lib/filters/sanitizer.py
++++ bleach/_vendor/html5lib/filters/sanitizer.py
+@@ -12,7 +12,7 @@ import re
+ import warnings
+ from xml.sax.saxutils import escape, unescape
+
+-from six.moves import urllib_parse as urlparse
++from bleach.six_shim import urllib_parse as urlparse
+
+ from . import base
+ from ..constants import namespaces, prefixes
+diff --git bleach/_vendor/html5lib/html5parser.py bleach/_vendor/html5lib/html5parser.py
+index 74d829d..b90a9fe 100644
+--- bleach/_vendor/html5lib/html5parser.py
++++ bleach/_vendor/html5lib/html5parser.py
+@@ -1,5 +1,5 @@
+ from __future__ import absolute_import, division, unicode_literals
+-from six import with_metaclass, viewkeys
++from bleach.six_shim import with_metaclass, viewkeys
+
+ import types
+
+diff --git bleach/_vendor/html5lib/serializer.py bleach/_vendor/html5lib/serializer.py
+index c66df68..5666f49 100644
+--- bleach/_vendor/html5lib/serializer.py
++++ bleach/_vendor/html5lib/serializer.py
+@@ -1,5 +1,5 @@
+ from __future__ import absolute_import, division, unicode_literals
+-from six import text_type
++from bleach.six_shim import text_type
+
+ import re
+
+diff --git bleach/_vendor/html5lib/treebuilders/base.py bleach/_vendor/html5lib/treebuilders/base.py
+index e4a3d71..2869da0 100644
+--- bleach/_vendor/html5lib/treebuilders/base.py
++++ bleach/_vendor/html5lib/treebuilders/base.py
+@@ -1,5 +1,5 @@
+ from __future__ import absolute_import, division, unicode_literals
+-from six import text_type
++from bleach.six_shim import text_type
+
+ from ..constants import scopingElements, tableInsertModeElements, namespaces
+
+diff --git bleach/_vendor/html5lib/treebuilders/etree.py bleach/_vendor/html5lib/treebuilders/etree.py
+index 086bed4..5ccfc4d 100644
+--- bleach/_vendor/html5lib/treebuilders/etree.py
++++ bleach/_vendor/html5lib/treebuilders/etree.py
+@@ -1,7 +1,7 @@
+ from __future__ import absolute_import, division, unicode_literals
+ # pylint:disable=protected-access
+
+-from six import text_type
++from bleach.six_shim import text_type
+
+ import re
+
+diff --git bleach/_vendor/html5lib/treebuilders/etree_lxml.py bleach/_vendor/html5lib/treebuilders/etree_lxml.py
+index e73de61..f462232 100644
+--- bleach/_vendor/html5lib/treebuilders/etree_lxml.py
++++ bleach/_vendor/html5lib/treebuilders/etree_lxml.py
+@@ -28,7 +28,7 @@ from . import etree as etree_builders
+ from .. import _ihatexml
+
+ import lxml.etree as etree
+-from six import PY3, binary_type
++from bleach.six_shim import PY3, binary_type
+
+
+ fullTree = True
+diff --git bleach/_vendor/html5lib/treewalkers/etree.py bleach/_vendor/html5lib/treewalkers/etree.py
+index 4465337..a9d9450 100644
+--- bleach/_vendor/html5lib/treewalkers/etree.py
++++ bleach/_vendor/html5lib/treewalkers/etree.py
+@@ -3,7 +3,7 @@ from __future__ import absolute_import, division, unicode_literals
+ from collections import OrderedDict
+ import re
+
+-from six import string_types
++from bleach.six_shim import string_types
+
+ from . import base
+ from .._utils import moduleFactoryFactory
+diff --git bleach/_vendor/html5lib/treewalkers/etree_lxml.py bleach/_vendor/html5lib/treewalkers/etree_lxml.py
+index a614ac5..ef42163 100644
+--- bleach/_vendor/html5lib/treewalkers/etree_lxml.py
++++ bleach/_vendor/html5lib/treewalkers/etree_lxml.py
+@@ -1,5 +1,5 @@
+ from __future__ import absolute_import, division, unicode_literals
+-from six import text_type
++from bleach.six_shim import text_type
+
+ from collections import OrderedDict
+

bleach/_vendor/html5lib/_inputstream.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import, division, unicode_literals
 
-from six import text_type
-from six.moves import http_client, urllib
+from bleach.six_shim import text_type
+from bleach.six_shim import http_client, urllib
 
 import codecs
 import re

bleach/_vendor/html5lib/_tokenizer.py

@@ -1,6 +1,6 @@
 from __future__ import absolute_import, division, unicode_literals
 
-from six import unichr as chr
+from bleach.six_shim import unichr as chr
 
 from collections import deque, OrderedDict
 from sys import version_info

bleach/_vendor/html5lib/_trie/py.py

@@ -1,5 +1,5 @@
 from __future__ import absolute_import, division, unicode_literals
-from six import text_type
+from bleach.six_shim import text_type
 
 from bisect import bisect_left
 

bleach/_vendor/html5lib/_utils.py

@@ -7,7 +7,7 @@
 except ImportError:
     from collections import Mapping
 
-from six import text_type, PY3
+from bleach.six_shim import text_type, PY3
 
 if PY3:
     import xml.etree.ElementTree as default_etree

bleach/_vendor/html5lib/filters/lint.py

@@ -1,6 +1,6 @@
 from __future__ import absolute_import, division, unicode_literals
 
-from six import text_type
+from bleach.six_shim import text_type
 
 from . import base
 from ..constants import namespaces, voidElements

bleach/_vendor/html5lib/filters/sanitizer.py

@@ -12,7 +12,7 @@
 import warnings
 from xml.sax.saxutils import escape, unescape
 
-from six.moves import urllib_parse as urlparse
+from bleach.six_shim import urllib_parse as urlparse
 
 from . import base
 from ..constants import namespaces, prefixes

bleach/_vendor/html5lib/html5parser.py

@@ -1,5 +1,5 @@
 from __future__ import absolute_import, division, unicode_literals
-from six import with_metaclass, viewkeys
+from bleach.six_shim import with_metaclass, viewkeys
 
 import types
 

bleach/_vendor/html5lib/serializer.py

@@ -1,5 +1,5 @@
 from __future__ import absolute_import, division, unicode_literals
-from six import text_type
+from bleach.six_shim import text_type
 
 import re
 

bleach/_vendor/html5lib/treebuilders/base.py

@@ -1,5 +1,5 @@
 from __future__ import absolute_import, division, unicode_literals
-from six import text_type
+from bleach.six_shim import text_type
 
 from ..constants import scopingElements, tableInsertModeElements, namespaces
 

bleach/_vendor/html5lib/treebuilders/etree.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import, division, unicode_literals
 # pylint:disable=protected-access
 
-from six import text_type
+from bleach.six_shim import text_type
 
 import re
 

bleach/_vendor/html5lib/treebuilders/etree_lxml.py

@@ -28,7 +28,7 @@
 from .. import _ihatexml
 
 import lxml.etree as etree
-from six import PY3, binary_type
+from bleach.six_shim import PY3, binary_type
 
 
 fullTree = True

bleach/_vendor/html5lib/treewalkers/etree.py

@@ -3,7 +3,7 @@
 from collections import OrderedDict
 import re
 
-from six import string_types
+from bleach.six_shim import string_types
 
 from . import base
 from .._utils import moduleFactoryFactory

bleach/_vendor/html5lib/treewalkers/etree_lxml.py

@@ -1,5 +1,5 @@
 from __future__ import absolute_import, division, unicode_literals
-from six import text_type
+from bleach.six_shim import text_type
 
 from collections import OrderedDict
 

bleach/_vendor/vendor_install.sh

@@ -8,6 +8,7 @@ BLEACH_VENDOR_DIR=${BLEACH_VENDOR_DIR:-"."}
 DEST=${DEST:-"."}
 
 pip install --no-binary all --no-compile --no-deps -r "${BLEACH_VENDOR_DIR}/vendor.txt" --target "${DEST}"
+(cd "${DEST}" && patch -p2 < 01_html5lib_six.patch)
 
 # install Python 3.6.14 urllib.urlparse for #536
 curl --proto '=https' --tlsv1.2 -o "${DEST}/parse.py" https://raw.githubusercontent.com/python/cpython/v3.6.14/Lib/urllib/parse.py

scripts/vendor_verify.sh

@@ -17,8 +17,11 @@ mkdir "${DEST}"
 # Get versions of pip and python
 pip --version
 
+# Copy patch files to dest directory
+cp bleach/_vendor/*.patch "${DEST}"
+
 # Install vendored dependencies into temp directory
-BLEACH_VENDOR_DIR=bleach/_vendor DEST="${DEST}" bleach/_vendor/vendor_install.sh
+BLEACH_VENDOR_DIR="bleach/_vendor" DEST="${DEST}" bleach/_vendor/vendor_install.sh
 
 # Diff contents of temp directory and bleach/_vendor/ excluding vendoring
 # infrastructure