fix(tmux): use `$...SESSION_NAME` while attaching (#10946)

plugins/tmux/tmux.plugin.zsh

@@ -73,7 +73,11 @@ function _zsh_tmux_plugin_run() {
   [[ "$ZSH_TMUX_UNICODE" == "true" ]] && tmux_cmd+=(-u)
 
   # Try to connect to an existing session.
-  [[ "$ZSH_TMUX_AUTOCONNECT" == "true" ]] && $tmux_cmd attach
+  if [[ -n "$ZSH_TMUX_DEFAULT_SESSION_NAME" ]]; then
+    [[ "$ZSH_TMUX_AUTOCONNECT" == "true" ]] && $tmux_cmd attach -t $ZSH_TMUX_DEFAULT_SESSION_NAME
+  else
+    [[ "$ZSH_TMUX_AUTOCONNECT" == "true" ]] && $tmux_cmd attach
+  fi
 
   # If failed, just run tmux, fixing the TERM variable if requested.
   if [[ $? -ne 0 ]]; then
@@ -83,9 +87,9 @@ function _zsh_tmux_plugin_run() {
       tmux_cmd+=(-f "$ZSH_TMUX_CONFIG")
     fi
     if [[ -n "$ZSH_TMUX_DEFAULT_SESSION_NAME" ]]; then
-        $tmux_cmd new-session -s $ZSH_TMUX_DEFAULT_SESSION_NAME
+      $tmux_cmd new-session -s $ZSH_TMUX_DEFAULT_SESSION_NAME
     else
-        $tmux_cmd new-session
+      $tmux_cmd new-session
     fi
   fi