Do not open tmux or winpty in --filter mode

src/core.go

@@ -38,6 +38,7 @@ func (r revision) compatible(other revision) bool {
 
 // Run starts fzf
 func Run(opts *Options) (int, error) {
+	if opts.Filter == nil {
 		if opts.Tmux != nil && len(os.Getenv("TMUX")) > 0 && opts.Tmux.index >= opts.Height.index {
 			return runTmux(os.Args, opts)
 		}
@@ -45,6 +46,7 @@ func Run(opts *Options) (int, error) {
 		if needWinpty(opts) {
 			return runWinpty(os.Args, opts)
 		}
+	}
 
 	if err := postProcessOptions(opts); err != nil {
 		return ExitError, err