Clarify that shadowbanned strings should be provided in lower-case.

And also make that check essentially be case-insentive as well as case-sensitive (check them both).

src/main/java/net/socialgamer/cah/util/ChatFilter.java

@@ -26,6 +26,7 @@ package net.socialgamer.cah.util;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
@@ -152,9 +153,12 @@ public class ChatFilter {
       }
     }
 
+    final String messageLower = message.toLowerCase(Locale.ENGLISH);
     // TODO keep track of how much someone does this and perma-shadowban them...
     for (final String banned : getShadowbanCharacters()) {
-      if (message.contains(banned)) {
+      // assume that the banned strings are already lowercase
+      // check both ways in case it decides lowercase of some unicode is not what we want though
+      if (message.contains(banned) || messageLower.contains(banned)) {
         LOG.info(String.format(
             "Dropping message '%s' from user %s (%s); contains banned string %s.", message,
             user.getNickname(), user.getHostname(), banned));

src/main/java/net/socialgamer/cah/util/ShadowBannedStringProvider.java

@@ -28,7 +28,8 @@ import java.util.Set;
 public interface ShadowBannedStringProvider {
   /**
    * A message that contains any string in this set should be silently dropped: not forwarded to any
-   * other user nor inform the originating user that the message was dropped.
+   * other user nor inform the originating user that the message was dropped. These should all be in
+   * lower-case unless the case matters for what they look like.
    */
   Set<String> getShadowBannedStrings();
 }