1 files changed, 3 insertions, 0 deletions
diff --git a/Swiften/IDN/LibIDNConverter.cpp b/Swiften/IDN/LibIDNConverter.cpp
index 2325015..e2a87be 100644
--- a/Swiften/IDN/LibIDNConverter.cpp
+++ b/Swiften/IDN/LibIDNConverter.cpp
@@ -72,17 +72,20 @@ SafeByteArray LibIDNConverter::getStringPrepared(const SafeByteArray& s, StringP
     }
     return createSafeByteArray(reinterpret_cast<const char*>(vecptr(preparedData)));
 }
 
 boost::optional<std::string> LibIDNConverter::getIDNAEncoded(const std::string& domain) {
     char* output;
     if (idna_to_ascii_8z(domain.c_str(), &output, IDNA_USE_STD3_ASCII_RULES) == IDNA_SUCCESS) {
         std::string result(output);
         free(output);
+        if (result.size() > 255) {
+            return boost::optional<std::string>();
+        }
         return result;
     }
     else {
         return boost::optional<std::string>();
     }
 }
 
 }