Fix emoji handling

Signal/src/Loki/Utilities/MentionUtilities.swift

@@ -17,8 +17,8 @@ public final class MentionUtilities : NSObject {
         var string = string
         let regex = try! NSRegularExpression(pattern: "@[0-9a-fA-F]*", options: [])
         let knownPublicKeys = MentionsManager.userPublicKeyCache[threadID] ?? [] // Should always be populated at this point
-        var mentions: [(range: NSRange, hexEncodedPublicKey: String)] = []
+        var mentions: [(range: NSRange, publicKey: String)] = []
-        var outerMatch = regex.firstMatch(in: string, options: .withoutAnchoringBounds, range: NSRange(location: 0, length: string.count))
+        var outerMatch = regex.firstMatch(in: string, options: .withoutAnchoringBounds, range: NSRange(location: 0, length: string.utf16.count))
         while let match = outerMatch {
             let publicKey = String((string as NSString).substring(with: match.range).dropFirst()) // Drop the @
             let matchEnd: Int
@@ -35,15 +35,15 @@ public final class MentionUtilities : NSObject {
                 }
                 if let displayName = displayName {
                     string = (string as NSString).replacingCharacters(in: match.range, with: "@\(displayName)")
-                    mentions.append((range: NSRange(location: match.range.location, length: displayName.count + 1), hexEncodedPublicKey: publicKey)) // + 1 to include the @
+                    mentions.append((range: NSRange(location: match.range.location, length: displayName.utf16.count + 1), publicKey: publicKey)) // + 1 to include the @
-                    matchEnd = match.range.location + displayName.count
+                    matchEnd = match.range.location + displayName.utf16.count
                 } else {
                     matchEnd = match.range.location + match.range.length
                 }
             } else {
                 matchEnd = match.range.location + match.range.length
             }
-            outerMatch = regex.firstMatch(in: string, options: .withoutAnchoringBounds, range: NSRange(location: matchEnd, length: string.count - matchEnd))
+            outerMatch = regex.firstMatch(in: string, options: .withoutAnchoringBounds, range: NSRange(location: matchEnd, length: string.utf16.count - matchEnd))
         }
         let result = NSMutableAttributedString(string: string, attributes: attributes)
         mentions.forEach { mention in