python-news escape fixes (#1822)

* Fix escapes in python-news posts

No longer escapes markdown inside of codeblocks or pre-escaped markdown.

Co-authored-by: Ryu18 <[email protected]>

* Add escaping to title of py-news posts

* Fix typo

Co-authored-by: Ryu18 <[email protected]>

1 files changed, 16 insertions, 5 deletions

diff --git a/bot/exts/info/python_news.py b/bot/exts/info/python_news.py
index 58dcd3a02..2a8b64f32 100644
--- a/bot/exts/info/python_news.py
+++ b/bot/exts/info/python_news.py
@@ -23,6 +23,14 @@ THREAD_URL = "https://mail.python.org/archives/list/{list}@python.org/thread/{id
 
 AVATAR_URL = "https://www.python.org/static/opengraph-icon-200x200.png"
 
+# By first matching everything within a codeblock,
+# when matching markdown it won't be within a codeblock
+MARKDOWN_REGEX = re.compile(
+    r"(?P<codeblock>`.*?`)"  # matches everything within a codeblock
+    r"|(?P<markdown>(?<!\\)[_|])",  # matches unescaped `_` and `|`
+    re.DOTALL  # required to support multi-line codeblocks
+)
+
 log = logging.getLogger(__name__)
 
 
@@ -76,8 +84,11 @@ class PythonNews(Cog):
 
     @staticmethod
     def escape_markdown(content: str) -> str:
-        """Escape the markdown underlines and spoilers."""
-        return re.sub(r"[_|]", lambda match: "\\" + match[0], content)
+        """Escape the markdown underlines and spoilers that aren't in codeblocks."""
+        return MARKDOWN_REGEX.sub(
+            lambda match: match.group("codeblock") or "\\" + match.group("markdown"),
+            content
+        )
 
     async def post_pep_news(self) -> None:
         """Fetch new PEPs and when they don't have announcement in #python-news, create it."""
@@ -109,7 +120,7 @@ class PythonNews(Cog):
 
             # Build an embed and send a webhook
             embed = discord.Embed(
-                title=new["title"],
+                title=self.escape_markdown(new["title"]),
                 description=self.escape_markdown(new["summary"]),
                 timestamp=new_datetime,
                 url=new["link"],
@@ -129,7 +140,7 @@ class PythonNews(Cog):
             self.bot.stats.incr("python_news.posted.pep")
 
             if msg.channel.is_news():
-                log.trace("Publishing PEP annnouncement because it was in a news channel")
+                log.trace("Publishing PEP announcement because it was in a news channel")
                 await msg.publish()
 
         # Apply new sent news to DB to avoid duplicate sending
@@ -179,7 +190,7 @@ class PythonNews(Cog):
 
                 # Build an embed and send a message to the webhook
                 embed = discord.Embed(
-                    title=thread_information["subject"],
+                    title=self.escape_markdown(thread_information["subject"]),
                     description=content[:1000] + f"... [continue reading]({link})" if len(content) > 1000 else content,
                     timestamp=new_date,
                     url=link,