sh: Add test for assignment errors (e.g. trying to change a readonly var). We currently ignore readonly status for assignments before regular builtins and external programs (these assignments are not persistent anyway), so just check that the readonly variable really is not changed. The test depends on the command builtin changes for 'command :'.
sh: Add test for assignment errors (e.g. trying to change a readonly var).
We currently ignore readonly status for assignments before regular builtins
and external programs (these assignments are not persistent anyway), so just
check that the readonly variable really is not changed.
The test depends on the command builtin changes for 'command :'.

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