If you're firmly wedded to 21.4, then you can use my Unicode-internal
fork of it instead. This has served me well for the last decade, and
has no data corruption bugs that I know of!
Unfortunately, the 21.4 series doesn't compile with recent gccs, and I
haven't yet got round to finding out the necessary changes.
Has anybody compiled any XEmacs on a recent (5.4) gcc?