small update to `xschem exit` function documentation

doc/xschem_man/developer_info.html

@@ -594,7 +594,8 @@ C {verilog_timescale.sym} 1050 -100 0 0 {name=s1 timestep="1ns" precision="1ns"
    escape tcl special characters with backslash </pre>
    <li><kbd>       exit [closewindow]</kbd></li><pre>
    Exit the program, ask for confirm if current file modified.
-   if 'closewindow' is given close the window, otherwise leave with a blank schematic </pre>
+   if 'closewindow' is given close the window, otherwise leave with a blank schematic
+   when closing the last remaining window </pre>
    <li><kbd>       expandlabel lab</kbd></li><pre>
    Expand vectored labels/instance names:
    xschem expandlabel {2*A[3:0]} --&gt; A[3],A[2],A[1],A[0],A[3],A[2],A[1],A[0] 8
@@ -1206,6 +1207,7 @@ C {verilog_timescale.sym} 1050 -100 0 0 {name=s1 timestep="1ns" precision="1ns"
 
 
 
+
  </ul>
 
   <!-- TCL global variables -->

src/scheduler.c

@@ -682,7 +682,8 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
 
     /* exit [closewindow]
      *   Exit the program, ask for confirm if current file modified.
-     *   if 'closewindow' is given close the window, otherwise leave with a blank schematic */
+     *   if 'closewindow' is given close the window, otherwise leave with a blank schematic
+     *   when closing the last remaining window */
     else if(!strcmp(argv[1], "exit"))
     {
       int closewindow = 0;