tools.func: use safe variable expansion in check_for_gh_release RETURN trap

ct/vaultwarden.sh

@@ -37,7 +37,7 @@ function update_script() {
     "2" "Set Admin Token")
 
   if [ "$UPD" == "1" ]; then
-    INSTALLED_VERSION="$(/opt/vaultwarden/bin/vaultwarden --version 2>/dev/null | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -n1 || true)"
+    INSTALLED_VERSION="$(/opt/vaultwarden/bin/vaultwarden --version 2>/dev/null | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -n1)"
     if [[ -n "$INSTALLED_VERSION" ]] &&
       ! grep -qxF "$INSTALLED_VERSION" "$HOME/.vaultwarden" 2>/dev/null; then
       printf '%s\n' "$INSTALLED_VERSION" >"$HOME/.vaultwarden"

misc/tools.func

@@ -2647,9 +2647,9 @@ check_for_gh_release() {
 
   ensure_dependencies jq
 
-  local gh_check_json
+  local gh_check_json=""
   gh_check_json=$(mktemp /tmp/tools-gh-check-XXXXXX) || return 73
-  trap 'rm -f "$gh_check_json"' RETURN
+  trap 'rm -f "${gh_check_json:-}"' RETURN
 
   # Build auth header if token is available
   local header_args=()