Thank you very much for your answer. I am interested in "all the details", thank you for the extensive answer. I did not immediately test your fix, as you were explicitly refering to Tcl versions 8.6 and 8.7. I simply thought, if you dont expect it to work for Tcl 8.5, for whatever reason, there is no point in setting up a HEAD-version test environment.
Anyhow, now I have compiled a NaviServer that has the same versions for all its components except for NaviServer itself (from 4.99.14 to 4.99.16d10/HEAD), and I can confirm that the problem disappears when using the HEAD version that includes your fix. The problem also disappears, when doing an append myvar "".
So, finally, the problem seems to be solved. I simply add the workaround and wait for the next NaviServer release.
Thank you, again, for your help!!
PS: Actually, the "culprit" in the "real code" was an ns_log line a few lines above (my log 3-[encoding convertfrom [ns_conn encoding] $interactionParams(preview)]). The problem disappears as well, when I simply remove that line. It seems to have a similar effect as the -translation binary in the artificial example.
