${p+\"$p\"}

[Dan Jacobson]

So how am I to get
"A"
with bash?

$ cat z
p=A
cat <<EOF
${p+\"$p\"}
${p+"$p"}
EOF
$ bash z
\"A\"
A
$ dash z
"A" <=========WANT THIS
A
$ bash --version
GNU bash, version 5.0.0(1)-release...