Bug#267142: posh not a /bin/sh candidate

[Thomas Hood <jdthood@aglu.demon.nl>]

Several DDs have said that they plan to continue to use "test -a"
and "test -o" in /bin/sh scripts.  Given this fact, it is necessary
for reliability that all shells that are /bin/sh candidates either
refrain from implementing a "test" builtin or else implement a
"test" builtin compatible with /usr/bin/test.

In other words, "test" cannot be "grandfathered" --- it cannot be
treated as an exception to the rule that shells should implement
builtins in mutually compatible ways.  (Such exceptions have to be
dealt with by scripts not using the options that behave differently
among shells, and/or by specifying a particular shell in the shebang.)

The only shell I know of that implements "test" incompatibly
with /usr/bin/test is posh.  (It has been alleged that different
shells have different precedence rules for the logical connective
options of "test", but no one has yet shown that any of the Debian
shells is different from the others.)  The maintainer of posh
refuses to consider his shell's deviance as a bug; so the conclusion
must be drawn that "posh" is not a practical /bin/sh candidate.
--
Thomas Hood