gui: Disallow creating zero sized nets

When creating bus rippers in 'net' style with zero-sized bus
ripper setting enabled in the previous commit, zero sized nets
were created as well.  This has been fixed by disabling creation
of zero sized net objects in such situations.

libleptongui/src/o_net.c

@@ -1,7 +1,7 @@
 /* Lepton EDA Schematic Capture
  * Copyright (C) 1998-2010 Ales Hvezda
  * Copyright (C) 1998-2016 gEDA Contributors
- * Copyright (C) 2017-2022 Lepton EDA Contributors
+ * Copyright (C) 2017-2024 Lepton EDA Contributors
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -1057,7 +1057,12 @@ int o_net_add_busrippers(GschemToplevel *w_current, LeptonObject *net_obj,
     }
 
     for (i = 0; i < ripper_count; i++) {
-      if (w_current->bus_ripper_type == NET_BUS_RIPPER) {
+      if ((w_current->bus_ripper_type == NET_BUS_RIPPER) &&
+          /* Don't add a new net if the coords are the same.
+           * Otherwise it will be zero sized. */
+          ! ((rippers[i].x[0] == rippers[i].x[1]) &&
+             (rippers[i].y[0] == rippers[i].y[1])))
+      {
         new_obj = lepton_net_object_new (NET_COLOR,
                                          rippers[i].x[0],
                                          rippers[i].y[0],