Make shrc work with set -u

roles/home-cli/files/shrc

@@ -1,7 +1,7 @@
 #!/bin/sh
 export ACP_SHRC=1
 
-if [ "$ZSH_VERSION" ]; then
+if [ "${ZSH_VERSION-none}" != "none" ]; then
         emulate sh -c 'source /etc/profile'
 fi
 
@@ -128,19 +128,19 @@ export POWERSHELL_TELEMETRY_OPTOUT=1
 export PYTHONWARNINGS="ignore::UserWarning"
 
 PS1="$ "
-if test -z "${HOST}"; then
+if [ "${HOST-invalid}" != "invalid" ]; then
     HOST="$(hostname 2>/dev/null || cat /etc/hostname)"
 fi
 if test $(id -u) -eq 0; then
-    export PS1="${HOST%%.*}# "
+    export PS1="${HOST-localhost%%.*}# "
 else
-    export PS1="${HOST%%.*}$ "
+    export PS1="${HOST-localhost%%.*}$ "
 fi
 if test -x /usr/bin/tty; then
     export GPG_TTY=$(tty)
 fi
 
-if [ "$BASH" ]; then
+if [ "${BASH-none}" != "none" ]; then
     HISTCONTROL=ignorespace:ignoredups
     shopt -s histappend
     bind '"\e[1;5C": forward-word'
@@ -157,7 +157,7 @@ if [ "$BASH" ]; then
     fi
 fi
 
-if [ "$ZSH_VERSION" ]; then
+if [ "${ZSH_VERSION-none}" != "none" ]; then
     # Command history.
     autoload -Uz compinit && compinit
     autoload -U history-search-end