Fix the behavior of 'readonly foo', caught by our own configure script!

test/gold.sh runs configure.  'test/gold.sh all' passes now.

Also add two related spec tests for 'local' behavior.

Test cleanup:

- Remove a test that was folded into here-doc.test.sh.
- Move spec/readonly.sh to gold/ and add it to the test/gold.sh driver.
  - We want to migrate all the shell scripts in the spec/ directory that
    aren't *.test.sh.

core/cmd_exec.py

@@ -690,30 +690,36 @@ def _Dispatch(self, node, fork_external):
        raise NotImplementedError(node.keyword)

      for pair in node.pairs:
        if pair.rhs:
          # RHS can be a string or array.
          val = self.ev.EvalWordToAny(pair.rhs)
          assert isinstance(val, runtime.value), val
        else:
          # 'local x' is equivalent to local x=""
          val = runtime.Str('')

        if pair.op == assign_op.PlusEqual:
          assert pair.rhs, pair.rhs  # I don't think a+= is valid?
          val = self.ev.EvalWordToAny(pair.rhs)
          old_val, lval = expr_eval.EvalLhs(pair.lhs, self.arith_ev, self.mem,
                                            self.exec_opts)
          sig = (old_val.tag, val.tag)
          if sig == (value_e.Str, value_e.Str):
          if sig == (value_e.Undef, value_e.Str):
            pass  # val is RHS
          elif sig == (value_e.Undef, value_e.StrArray):
            pass  # val is RHS
          elif sig == (value_e.Str, value_e.Str):
            val = runtime.Str(old_val.s + val.s)
          elif sig == (value_e.Str, value_e.StrArray):
            e_die("Can't append array to string")
          elif sig == (value_e.StrArray, value_e.Str):
            e_die("Can't append string to array")
          elif sig == (value_e.StrArray, value_e.StrArray):
            val = runtime.StrArray(old_val.strs + val.strs)
        else:

        else:  # plain assignment
          lval = self._EvalLhs(pair.lhs)

        #log('ASSIGNING %s -> %s', lval, val)
          # RHS can be a string or array.
          if pair.rhs:
            val = self.ev.EvalWordToAny(pair.rhs)
            assert isinstance(val, runtime.value), val
          else:
            # e.g. 'readonly x' or 'local x'
            val = None  # only changing flags

        self.mem.SetVar(lval, val, flags, lookup_mode)

      # TODO: This should be eval of RHS, unlike bash!

core/state.py

@@ -410,7 +410,7 @@ def SetVar(self, lval, value, new_flags, lookup_mode):
          cell.readonly = True
      else:
        if value is None:
          value = runtime.Str('')  # export foo, readonly foo
          value = runtime.Undef()  # export foo, readonly foo
        cell = runtime.cell(value,
                            var_flags.Exported in new_flags ,
                            var_flags.ReadOnly in new_flags )

spec/readonly.sh → gold/readonly.sh

@@ -1,7 +1,4 @@
#!/usr/bin/env bash
#
# Usage:
#   ./readonly.sh <function name>

set -o nounset
set -o pipefail
@@ -14,6 +11,7 @@ f1() {

  readonly foo  # not anymore
  #foo=2  # would cause an exception
  echo $foo

  echo done

spec/builtin-vars.test.sh

@@ -218,3 +218,22 @@ echo "${a[@]}" len="${#a[@]}"
# stdout: x z len=2
# N-I dash status: 2
# N-I dash stdout-json: ""

### Use local twice
f() {
  local foo=bar
  local foo
  echo $foo
}
f
# stdout: bar

### Local without variable is still unset!
set -o nounset
f() {
  local foo
  echo "[$foo]"
}
f
# status: 1
# OK dash status: 2

test/gold.sh

@@ -76,7 +76,7 @@ gen-module-init() {
}

wild() {
  _compare test/wild.sh parse-usr-bin
  _compare test/wild.sh all '^distro/usr-bin'
}

# NOTE: zsh behaves differently under sh and bin/osh!  Looks like it is an
@@ -96,17 +96,26 @@ nix() {
  _compare gold/nix.sh isElfSimpleWithStdin
}

readonly_() {
  _compare gold/readonly.sh
}

all() {
  readonly_
  version-text
  count
  one-spec-test
  html-summary
  configure
  no-op
  gen-module-init
  wild
  startup-benchmark
  glob
  # This one takes a little long, but it's realistic.
  wild

  # There are slight differences in the number of syscalls reported.  Not sure
  # of the cause.
  #startup-benchmark
}

"$@"

test/spec.sh

@@ -420,7 +420,7 @@ arith-context() {
}

array() {
  sh-spec spec/array.test.sh --osh-failures-allowed 11 \
  sh-spec spec/array.test.sh --osh-failures-allowed 10 \
    $BASH $MKSH $OSH "$@"
}