Index: trunk/src/netlist.c
===================================================================
--- trunk/src/netlist.c	(revision 927)
+++ trunk/src/netlist.c	(revision 928)
@@ -295,10 +295,10 @@
 	}
 
 
-	rats_patch_append(PCB, RATP_DEL_CONN, pins[0], nets[0]->Name+2);
-	rats_patch_append(PCB, RATP_DEL_CONN, pins[1], nets[1]->Name+2);
-	rats_patch_append(PCB, RATP_ADD_CONN, pins[0], nets[1]->Name+2);
-	rats_patch_append(PCB, RATP_ADD_CONN, pins[1], nets[0]->Name+2);
+	rats_patch_append_optimize(PCB, RATP_DEL_CONN, pins[0], nets[0]->Name+2);
+	rats_patch_append_optimize(PCB, RATP_DEL_CONN, pins[1], nets[1]->Name+2);
+	rats_patch_append_optimize(PCB, RATP_ADD_CONN, pins[0], nets[1]->Name+2);
+	rats_patch_append_optimize(PCB, RATP_ADD_CONN, pins[1], nets[0]->Name+2);
 
 	/* TODO: not very efficient to regenerate the whole list... */
 	rats_patch_make_edited(PCB);
Index: trunk/src/rats_patch.c
===================================================================
--- trunk/src/rats_patch.c	(revision 927)
+++ trunk/src/rats_patch.c	(revision 928)
@@ -1,5 +1,7 @@
 #include "rats_patch.h"
 
+static void rats_patch_remove(PCBTypePtr pcb, rats_patch_line_t *n, int do_free);
+
 void rats_patch_append(PCBTypePtr pcb, rats_patch_op_t op, const char *id, const char *a1, const char *a2)
 {
 	rats_patch_line_t *n;
@@ -25,6 +27,40 @@
 	n->next = NULL;
 }
 
+void rats_patch_append_optimize(PCBTypePtr pcb, rats_patch_op_t op, const char *id, const char *a1, const char *a2)
+{
+	rats_patch_op_t seek_op;
+	rats_patch_line_t *n;
+
+	switch(op) {
+		case RATP_ADD_CONN:      seek_op = RATP_DEL_CONN; break;
+		case RATP_DEL_CONN:      seek_op = RATP_ADD_CONN; break;
+		case RATP_CHANGE_ATTRIB: seek_op = RATP_CHANGE_ATTRIB; break;
+	}
+
+	/* keep the list clean: remove the last operation that becomes obsolete by the new one */
+	for(n = pcb->NetlistPatchLast; n != NULL; n = n->prev) {
+		if ((n->op == seek_op) && (strcmp(n->id, id) == 0)) {
+			switch(op) {
+				case RATP_CHANGE_ATTRIB:
+					if (strcmp(n->arg1.attrib_name, a1) != 0)
+						break;
+					rats_patch_remove(pcb, n, 1);
+					goto quit;
+				case RATP_ADD_CONN:
+				case RATP_DEL_CONN:
+					if (strcmp(n->arg1.net_name, a1) != 0)
+						break;
+					rats_patch_remove(pcb, n, 1);
+					goto quit;
+			}
+		}
+	}
+
+	quit:;
+	rats_patch_append(pcb, op, id, a1, a2);
+}
+
 /* Unlink n from the list; if do_free is non-zero, also free fields and n */
 static void rats_patch_remove(PCBTypePtr pcb, rats_patch_line_t *n, int do_free)
 {
Index: trunk/src/rats_patch.h
===================================================================
--- trunk/src/rats_patch.h	(revision 927)
+++ trunk/src/rats_patch.h	(revision 928)
@@ -1,6 +1,12 @@
 #include "global.h"
+
+/* Allocate and append a patch line to the patch list */
 void rats_patch_append(PCBTypePtr pcb, rats_patch_op_t op, const char *id, const char *a1, const char *a2);
 
+/* Same as rats_patch_append() but also optimize previous entries so that
+   redundant entries are removed */
+void rats_patch_append_optimize(PCBTypePtr pcb, rats_patch_op_t op, const char *id, const char *a1, const char *a2);
+
 /* Create [NETLIST_EDITED] from [NETLIST_INPUT] applying the patch */
 void rats_patch_make_edited(PCBTypePtr pcb);