fix for posix semantics for the := word expansion when assigning array elements

tests/array.right

@@ -773,3 +773,15 @@ declare -A foo=([v]=$'\001\001\001\001' )
 declare -A foo=([v]=$'\001\001\001\001' )
 declare -A foo=([$'\001']=$'ab\001c' )
 declare -A foo=([$'\001']=$'ab\001c' )
+foo
+declare -a a=([42]="foo")
+foo
+declare -a a=([42]="foo")
+7
+declare -ai a=([42]="7")
+42
+declare -ai a=([42]="42")
+FOO
+declare -Au A=([Darwin]="FOO" )
+FOO
+declare -Au A=(["@"]="FOO" )

tests/array.tests

@@ -426,3 +426,4 @@ ${THIS_SH} ./array26.sub
 ${THIS_SH} ./array27.sub
 ${THIS_SH} ./array28.sub
 ${THIS_SH} ./array29.sub
+${THIS_SH} ./array30.sub

tests/array30.sub

@@ -0,0 +1,46 @@
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+declare -a a
+a=()
+
+echo ${a[42]=foo}
+declare -p a
+
+a=()
+echo ${a[$(echo 42)]=foo}
+declare -p a
+
+unset a
+
+declare -ai a
+a=()
+echo ${a[42]=4+3}
+declare -p a
+
+a=()
+echo ${a[$(echo 42)]=42}
+declare -p a
+
+unset a
+
+declare -A A
+declare -u A
+A=()
+echo ${A[$(echo Darwin)]=foo}
+
+declare -p A
+A=()
+
+echo ${A[@]:=foo}
+declare -p A

tests/exp.right

@@ -409,3 +409,11 @@ cdefg
 abcdefg
 abcde
 abcdefg
+foo
+declare -- a="foo"
+7
+declare -i a="7"
+42
+declare -- a="42"
+FOO
+declare -u A="FOO"

tests/exp.tests

@@ -423,3 +423,4 @@ ${THIS_SH} ./exp9.sub
 ${THIS_SH} ./exp10.sub
 ${THIS_SH} ./exp11.sub
 ${THIS_SH} ./exp12.sub
+${THIS_SH} ./exp13.sub

tests/exp13.sub

@@ -0,0 +1,34 @@
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+unset a
+
+echo ${a:=foo}
+declare -p a
+
+unset a
+
+declare -i a
+echo ${a:=4+3}
+declare -p a
+
+unset a
+echo ${a:=42}
+declare -p a
+
+unset a
+declare -u A
+A=
+echo ${A:=foo}
+
+declare -p A