refactor: drop dead weight (unused param, duplicate checks, dead code)

- tmux_party_setup_server took an unused name parameter; drop it.
- validate_party_name ran two separate case blocks with a length
  check between them; merge into one case now that the length check
  (which an empty name always passes) runs first.
- roster_read now applies the RR_GROUP fallback to TMUX_PARTY_GROUP
  once, so cmd_join, cmd_invite, and cmd_list no longer each repeat
  ${RR_GROUP:-$TMUX_PARTY_GROUP}.
- socket_path had no caller in party; remove it and its test.

party

@@ -103,16 +103,18 @@ EOF
 # name as a flag, so such a party could never be addressed.
 validate_party_name() {
     name="$1"
-    case "$name" in
-        '' )  echo "party: name must not be empty" >&2; return 2 ;;
-    esac
     # Length cap: 63 keeps the full socket path comfortably below the
-    # 108-char sun_path limit for typical USERs.
+    # 108-char sun_path limit for typical USERs. Runs before the empty/
+    # shape checks below; an empty name has length 0, so it always
+    # passes this check and falls through to the '' case there.
     if [ "${#name}" -gt 63 ]; then
         echo "party: name '$name' too long (max 63 chars)" >&2
         return 2
     fi
     case "$name" in
+        '' )
+            echo "party: name must not be empty" >&2
+            return 2 ;;
         -* )
             echo "party: name must not start with '-'" >&2
             return 2 ;;
@@ -200,10 +202,6 @@ roster_record_path() {
     printf '%s/roster\n' "$(party_dir_path "$1" "$2")"
 }
 
-socket_path() {
-    printf '%s/sock\n' "$(party_dir_path "$1" "$2")"
-}
-
 # Roster I/O
 # ----------
 #
@@ -326,6 +324,10 @@ roster_read() {
             '' | \#*)   ;;
         esac
     done < "$rec"
+    # A roster written before --group existed (or otherwise missing
+    # GROUP=) gates on the default group; callers can rely on RR_GROUP
+    # always naming the party's actual perimeter.
+    [ -n "$RR_GROUP" ] || RR_GROUP=$TMUX_PARTY_GROUP
     return 0
 }
 
@@ -565,7 +567,7 @@ party_self_path() {
 # All commands run against -S "$sock". Every literal name embedded
 # is shell-quoted to survive tmux's parser.
 tmux_party_setup_server() {
-    sock="$1" name="$2"
+    sock="$1"
 
     # Write a tiny notification helper next to the socket. The leading dot
     # keeps it out of typical `ls` listings. The per-party private dir
@@ -872,7 +874,7 @@ EOF
     # apply_party_perms_file widens it AFTER server-access -aw runs.
     "$PARTY_TMUX" -S "$sock" new-session -d -s "$name"
 
-    tmux_party_setup_server "$sock" "$name"
+    tmux_party_setup_server "$sock"
 
     # Auth gate FIRST, server-access runs BEFORE we widen FS perms.
     # This closes the connect-before-allowlist race: without this order,
@@ -1192,7 +1194,7 @@ EOF
     # segments.
     : >> "$logfile"
     chmod 0640 "$logfile"
-    chgrp "${RR_GROUP:-$TMUX_PARTY_GROUP}" "$logfile"
+    chgrp "$RR_GROUP" "$logfile"
 
     # Filter to unpiped panes ourselves rather than trusting `-o` to
     # skip them: on tmux 3.5a, `-o` toggles an existing pipe closed
@@ -1253,10 +1255,9 @@ EOF
     # FS perimeter on the per-party dir already blocks non-group readers
     # at roster_list; this preflight just turns that into a friendlier
     # error than "party not found" when membership is the actual cause.
-    party_group="${RR_GROUP:-$TMUX_PARTY_GROUP}"
+    if ! user_in_group "$USER" "$RR_GROUP"; then
-    if ! user_in_group "$USER" "$party_group"; then
         cat >&2 <<EOF
-party: '$RR_PARTY_NAME' uses group '$party_group'; you ($USER) are not a member.
+party: '$RR_PARTY_NAME' uses group '$RR_GROUP'; you ($USER) are not a member.
 
 Ask the host or your sysadmin to add you, then log out and back in.
 EOF
@@ -1469,12 +1470,11 @@ cmd_invite() {
     # the guest sees a write(1) ping, but `party join` reports not-found.
     # Warn-and-proceed (rather than hard-fail) so a later usermod -aG
     # doesn't require a re-invite.
-    invite_group="${RR_GROUP:-$TMUX_PARTY_GROUP}"
+    if ! user_in_group "$user" "$RR_GROUP"; then
-    if ! user_in_group "$user" "$invite_group"; then
         cat >&2 <<EOF
-party invite: warning, '$user' is not in group '$invite_group'.
+party invite: warning, '$user' is not in group '$RR_GROUP'.
   They will not be able to discover or join until added.
-  Run: sudo usermod -aG $invite_group $user (and have them relog).
+  Run: sudo usermod -aG $RR_GROUP $user (and have them relog).
 EOF
     fi
 
@@ -1576,15 +1576,14 @@ cmd_list() {
         # metadata leak; it only stops `party list` from DISPLAYING parties
         # whose group the caller isn't in. Confidentiality still rides on
         # the FS perimeter alone.
-        list_group="${RR_GROUP:-$TMUX_PARTY_GROUP}"
+        printf '%s\n' "$_ls_groups" | grep -qx "$RR_GROUP" || continue
-        printf '%s\n' "$_ls_groups" | grep -qx "$list_group" || continue
         # The group tag only earns its column when the visible parties
         # disagree on it. Which group gates a party is decided per host
         # (auto-selection), so there is no default to compare against:
         # tag every line, then strip the tags below unless they differ.
-        [ -n "$first_group" ] || first_group="$list_group"
+        [ -n "$first_group" ] || first_group="$RR_GROUP"
-        [ "$list_group" = "$first_group" ] || mixed=1
+        [ "$RR_GROUP" = "$first_group" ] || mixed=1
-        group_tag=" [group=$list_group]"
+        group_tag=" [group=$RR_GROUP]"
         if [ "$state" = ok ]; then
             attendees=$("$PARTY_TMUX" -S "$RR_SOCKET" list-clients 2>/dev/null | wc -l | tr -d ' ')
             line=$(printf '%-12s %-30s %s attendee(s)%s' \

tests/30-roster.bats

@@ -17,11 +17,6 @@ setup() {
   [ "$out" = "$PARTY_SOCKET_DIR/party-veg:debug-the-deploy.d" ]
 }
 
-@test "socket_path lives inside the per-party private dir" {
-  out=$(socket_path "veg" "debug-the-deploy")
-  [ "$out" = "$PARTY_SOCKET_DIR/party-veg:debug-the-deploy.d/sock" ]
-}
-
 @test "roster_write then roster_read round-trips all fields" {
   ensure_party_dir "$USER" "rt-test"
   rec=$(roster_record_path "$USER" "rt-test")