diff --git a/src/netlist.c b/src/netlist.c
index 9c074bff..5a832c6f 100644
--- a/src/netlist.c
+++ b/src/netlist.c
@@ -1057,6 +1057,7 @@ int compare_schematics(const char *f)
   char current_sch[PATH_MAX];
   int ret=0; /* ret==0 means no differences found */
 
+  save(0);
   if(f == NULL) {
     tcleval("load_file_dialog {Schematic to compare with} .sch.sym INITIALLOADDIR");
     if(tclresult()[0]) my_strncpy(xctx->sch_to_compare, tclresult(), S(xctx->sch_to_compare));
diff --git a/src/scheduler.c b/src/scheduler.c
index 9a5b1d72..df7dc660 100644
--- a/src/scheduler.c
+++ b/src/scheduler.c
@@ -989,9 +989,12 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      else if(!strcmp(argv[2],"textlayer")) {
        Tcl_SetResult(interp, my_itoa(TEXTLAYER), TCL_VOLATILE);
      }
+     /* top_path="" for main window, ".x1", ".x2", ... for additional windows.
+      * always "" in tabbed interface */
      else if(!strcmp(argv[2],"top_path")) {
        Tcl_SetResult(interp, xctx->top_path, TCL_VOLATILE);
      }
+     /* same as above but main window returned as "." */
      else if(!strcmp(argv[2],"topwindow")) {
        char *top_path;
        top_path =  xctx->top_path[0] ? xctx->top_path : ".";