With the amount of time spent so far explaining the internal workings of sqlite's utf8 handling (which is not under fire in this year-old thread), I estimate that the tcl sqlite extension could have been patched at least 172 times so that it no longer inserts modified utf8. The only complication is that changing the serialisation format may constitute a breaking change to the extension's API, or at least a weird subtle surprise for any tcl users who have existing databases that do containing modified utf8 strings with embedded NUL characters, as a round trip from DB(modified utf8) -> tcl -> Tcl_UtfToExternal -> DB(standard utf8) will change the length of such data cells. Then there's the question of what happens when someone runs an old version of the tcl extension against a DB containing the new serialisation format...