Op 27-02-17 om 21:08 schreef Martijn Dekker:
> Shell reserved words (a.k.a. shell keywords) such as "if" are harder to
> fix. The single_quote() routine, if told to quote conditionally, would
> have to iterate through the internal list of shell reserved words and
> quote the string if it matches one of those. I will see if I can make
> that happen.

Here is a version that does that, and removes '=' and '!' from the list
of shell-safe characters. This should fix all the issues you were
reporting, hopefully making the xtrace output completely safe for shell
re-entry. It introduces a new function is_kwd() that checks if a string
is identical to a shell keyword/reserved word.

Attached are two patches: one incremental to my previous one, and one
against pristine dash 0.5.9.1.

- M.