Remove casing in domain filtering (#2654)

The extraction of domains from a message in the filterlist removes casing, but the checks of individual filters kept theirs, which led to some filters not working.

This assumes that two URLs that differ only by casing are identical, which isn't necessarily true, but a conflict is very unlikely.

1 files changed, 2 insertions, 2 deletions

diff --git a/bot/exts/filtering/_filters/domain.py b/bot/exts/filtering/_filters/domain.py
index ac9cc9018..c3f7f2886 100644
--- a/bot/exts/filtering/_filters/domain.py
+++ b/bot/exts/filtering/_filters/domain.py
@@ -36,11 +36,11 @@ class DomainFilter(Filter):
 
     async def triggered_on(self, ctx: FilterContext) -> bool:
         """Searches for a domain within a given context."""
-        domain = tldextract.extract(self.content).registered_domain
+        domain = tldextract.extract(self.content).registered_domain.lower()
 
         for found_url in ctx.content:
             extract = tldextract.extract(found_url)
-            if self.content in found_url and extract.registered_domain == domain:
+            if self.content.lower() in found_url and extract.registered_domain == domain:
                 if self.extra_fields.only_subdomains:
                     if not extract.subdomain and not urlparse(f"https://{found_url}").path:
                         return False