dependencies: Upgrade katex from 0.10.2 to 0.11.1.

Signed-off-by: Anders Kaseorg <anders@zulipchat.com>

package.json

@@ -34,7 +34,7 @@
     "jquery": "^3.4.1",
     "jquery-caret-plugin": "^1.5.2",
     "jquery-validation": "^1.19.0",
-    "katex": "^0.10.2",
+    "katex": "^0.11.1",
     "mini-css-extract-plugin": "^0.6.0",
     "moment": "^2.24.0",
     "moment-timezone": "^0.5.25",

version.py

@@ -26,4 +26,4 @@ LATEST_RELEASE_ANNOUNCEMENT = "https://blog.zulip.org/2019/03/01/zulip-2-0-relea
 #   historical commits sharing the same major version, in which case a
 #   minor version bump suffices.
 
-PROVISION_VERSION = '63.0'
+PROVISION_VERSION = '64.0'

yarn.lock

@@ -6573,10 +6573,10 @@ jsprim@^1.2.2:
     json-schema "0.2.3"
     verror "1.10.0"
 
-katex@^0.10.2:
-  version "0.10.2"
-  resolved "https://registry.yarnpkg.com/katex/-/katex-0.10.2.tgz#39973edbb65eda5b6f9e7f41648781e557dd4932"
-  integrity sha512-cQOmyIRoMloCoSIOZ1+gEwsksdJZ1EW4SWm3QzxSza/QsnZr6D4U1V9S4q+B/OLm2OQ8TCBecQ8MaIfnScI7cw==
+katex@^0.11.1:
+  version "0.11.1"
+  resolved "https://registry.yarnpkg.com/katex/-/katex-0.11.1.tgz#df30ca40c565c9df01a466a00d53e079e84ffaa2"
+  integrity sha512-5oANDICCTX0NqYIyAiFCCwjQ7ERu3DQG2JFHLbYOf+fXaMoH8eg/zOq5WSYJsKMi/QebW+Eh3gSM+oss1H/bww==
   dependencies:
     commander "^2.19.0"
 

zerver/lib/bugdown/__init__.py

@@ -14,6 +14,7 @@ import os
 import html
 import time
 import functools
+from io import StringIO
 import ujson
 import xml.etree.cElementTree as etree
 from xml.etree.cElementTree import Element
@@ -1311,7 +1312,18 @@ class Tex(markdown.inlinepatterns.Pattern):
     def handleMatch(self, match: Match[str]) -> Element:
         rendered = render_tex(match.group('body'), is_inline=True)
         if rendered is not None:
-            return etree.fromstring(rendered.encode('utf-8'))
+            # We need to give Python-Markdown an ElementTree object, but if we
+            # give it one with correctly stored XML namespaces, it will mangle
+            # everything when serializing it.  So we play this stupid game to
+            # store xmlns as a normal attribute.  :-[
+            assert ' zulip-xmlns="' not in rendered
+            rendered = rendered.replace(' xmlns="', ' zulip-xmlns="')
+            parsed = etree.iterparse(StringIO(rendered))
+            for event, elem in parsed:
+                if 'zulip-xmlns' in elem.attrib:
+                    elem.attrib['xmlns'] = elem.attrib.pop('zulip-xmlns')
+                root = elem
+            return root
         else:  # Something went wrong while rendering
             span = markdown.util.etree.Element('span')
             span.set('class', 'tex-error')