Make plots only close only if they are made

Author: jgray-19

src/madl_plot.mad

@@ -332,7 +332,9 @@ local function teardown_cmd (self, file, fname)
     then gnuplot_mv(fname, scrdump)
     else gnuplot_rm(fname)
     end
-    if close_plots then atexit(\-> kill_plots(self)) end
+    if close_plots and is_number(output) or is_nil(output) then 
+      atexit(\-> kill_plots(self)) 
+    end
   else
     if is_string(scrdump) then
       os.rename(fname, scrdump)