Followup: the issue lies with dash's echo builtin, not with the parser. The software that triggered the issue has not been used in four years. I don't know whether dash has changed in that time or if /bin/sh was different four years ago.
In any case, the echo builtin is behaving consistently with the dash man page, so I cannot blame dash for anything. I apologize for the noise---please close this bug report. Norman Ramsey
