Retain the PS1 across su(1) and sudo(8)

The shell start-up scripts are where the PS1 is meant to be set. So
far, the absence of a toolbox-specific start-up script was being worked
around by setting the PS1 as part of the 'podman exec' invocation. This
came with certain limitations. eg., using su(1) or sudo(8) to get a
root shell can overwrite the PS1 set during 'podman exec' with a value
set by the operating system's existing start-up scripts depending on
which environment variables were being retained.

Now that the toolbox has it's own /etc/profile.d/toolbox.sh start-up
script, it's time to move the PS1 to its rightful home.

Since the start-up script and /run/.toolboxenv are present in older
toolbox containers, this change should be fully backwards compatible
and lead to a more robust PS1 without breaking older containers.

https://github.com/debarshiray/toolbox/pull/148

profile.d/toolbox.sh

@@ -24,23 +24,26 @@ if [ -f /run/ostree-booted ] \
 fi
 
 if [ -f /run/.containerenv ] \
-   && ! [ -f "$toolbox_welcome_stub" ] \
    && [ -f /run/.toolboxenv ]; then
-    echo ""
-    echo "Welcome to the Toolbox; a container where you can install and run"
-    echo "all your tools."
-    echo ""
-    echo " - Use DNF in the usual manner to install command line tools."
-    echo " - To create a new tools container, run 'toolbox create'."
-    echo ""
-    printf "For more information, see the "
-    # shellcheck disable=SC1003
-    printf '\033]8;;https://docs.fedoraproject.org/en-US/fedora-silverblue/toolbox/\033\\documentation\033]8;;\033\\'
-    printf ".\n"
-    echo ""
+    PS1="🔹[\u@\h \W]\\$ "
 
-    mkdir -p "$toolbox_config"
-    touch "$toolbox_welcome_stub"
+    if ! [ -f "$toolbox_welcome_stub" ]; then
+        echo ""
+        echo "Welcome to the Toolbox; a container where you can install and run"
+        echo "all your tools."
+        echo ""
+        echo " - Use DNF in the usual manner to install command line tools."
+        echo " - To create a new tools container, run 'toolbox create'."
+        echo ""
+        printf "For more information, see the "
+        # shellcheck disable=SC1003
+        printf '\033]8;;https://docs.fedoraproject.org/en-US/fedora-silverblue/toolbox/\033\\documentation\033]8;;\033\\'
+        printf ".\n"
+        echo ""
+
+        mkdir -p "$toolbox_config"
+        touch "$toolbox_welcome_stub"
+    fi
 fi
 
 unset toolbox_config

toolbox

@@ -66,7 +66,6 @@ toolbox_container_default=""
 toolbox_container_old=""
 toolbox_container_prefix_default=""
 toolbox_image=""
-toolbox_prompt="🔹[\u@\h \W]\\$ "
 user_id_real=$(id -ru 2>&3)
 verbose=false
 
@@ -1107,11 +1106,7 @@ enter()
             --interactive \
             --tty \
             "$toolbox_container" \
-            capsh --caps="" -- -c 'cd "$1"; export PS1="$2"; shift 2; exec "$@"' \
-                    /bin/sh \
-                    "$PWD" \
-                    "$toolbox_prompt" \
-                    "$shell_to_exec" -l 2>&3
+            capsh --caps="" -- -c 'cd "$1"; shift; exec "$@"' /bin/sh "$PWD" "$shell_to_exec" -l 2>&3
 )