@ -1014,6 +1014,10 @@ stardict_longest_common_collation_prefix (StardictDict *sd,
u_strFromUTF8 (NULL, 0, &uc2_len, s2, -1, &error);
error = U_ZERO_ERROR;
// Prevent undefined behaviour with VLAs.
if (!uc1_len || !uc2_len)
return 0;
UChar uc1[uc1_len];
UChar uc2[uc2_len];
u_strFromUTF8 (uc1, uc1_len, NULL, s1, -1, &error);