Exclude strikethrough text from comment excerpts

tildes/tests/test_comment.py

@@ -130,6 +130,14 @@ def test_comment_excerpt_excludes_blockquote(topic, session_user):
     assert comment.excerpt == "Yeah, I agree."
 
 
+def test_comment_excerpt_excludes_del(topic, session_user):
+    """Ensure that comment excerpts don't include text from strikethrough (<del>)."""
+    markdown = "I really ~~hate~~ love it."
+    comment = Comment(topic, session_user, markdown)
+
+    assert comment.excerpt == "I really love it."
+
+
 def test_comment_tree(db, topic, session_user):
     """Ensure that building and pruning a comment tree works."""
     all_comments = []

tildes/tildes/models/comment/comment.py

@@ -109,7 +109,7 @@ class Comment(DatabaseModel):
         self.rendered_html = convert_markdown_to_safe_html(new_markdown)
 
         extracted_text = extract_text_from_html(
-            self.rendered_html, skip_tags=["blockquote"]
+            self.rendered_html, skip_tags=["blockquote", "del"]
         )
         self.excerpt = truncate_string(
             extracted_text, length=200, truncate_at_chars=" "