Index: trunk/src_plugins/import_mucs/mucs.c
===================================================================
--- trunk/src_plugins/import_mucs/mucs.c	(revision 6808)
+++ trunk/src_plugins/import_mucs/mucs.c	(revision 6809)
@@ -43,6 +43,8 @@
 #include "action_helper.h"
 #include "hid_actions.h"
 #include "plugins.h"
+#include "layer.h"
+#include "conf_core.h"
 
 static const char *mucs_cookie = "mucs importer";
 
@@ -55,19 +57,18 @@
 	FILE *fi;
 	int c, c2;
 	pcb_coord_t x1, y1, x2, y2, r;
-/*
-	pcb_layer_id_t *layer_list;	
-	int layer_list_length;
-
-	pcb_layer_list(PCB_LYT_COPPER, layer_list, layer_list_length);
-*/
 	fname = argc ? argv[0] : 0;
 
+	if (!(pcb_layer_flags(INDEXOFCURRENT) & PCB_LYT_COPPER)) {
+		pcb_message(PCB_MSG_ERROR, "The currently active layer is not a copper layer.\n");
+	}
+
+
 	if (!fname || !*fname) {
 		fname = pcb_gui->fileselect("Load mucs routing session Resource File...",
 																"Picks a mucs session resource file to load.\n"
 																	"This file could be generated by mucs-pcb\n",
-																default_file, ".pl", "unixplot", HID_FILESELECT_READ);
+																default_file, ".l1", "unixplot", HID_FILESELECT_READ);
 		if (fname == NULL)
 			PCB_ACT_FAIL(LoadMucsFrom);
 		if (default_file != NULL) {
@@ -102,7 +103,7 @@
 				y2 = (getc(fi) + (getc(fi) * 256));
 				pcb_trace("Line(%d %d %d %d 20 \" \")\n", x1, y1, x2, y2);
 				/* consider a bounds checking function to censor absurd coord sizes */
-				pcb_line_new(&PCB->Data->Layer[0], PCB_MIL_TO_COORD(x1), PCB_MIL_TO_COORD(y1), PCB_MIL_TO_COORD(x2), PCB_MIL_TO_COORD(y2), PCB_MIL_TO_COORD(10), PCB_MIL_TO_COORD(10), pcb_flag_make(PCB_FLAG_AUTO));
+				pcb_line_new(CURRENT, PCB_MIL_TO_COORD(x1), PCB_MIL_TO_COORD(y1), PCB_MIL_TO_COORD(x2), PCB_MIL_TO_COORD(y2), PCB_MIL_TO_COORD(10), PCB_MIL_TO_COORD(10), pcb_flag_make(PCB_FLAG_AUTO));
 				break;
 			case 'c':
 				x1 = (getc(fi) + (getc(fi) * 256));
@@ -115,7 +116,7 @@
 				x1 = (getc(fi) + (getc(fi) * 256));
 				y1 = (getc(fi) + (getc(fi) * 256));
 				pcb_trace("Line(%d %d %d %d 20 \" \")\n", x1, y1, x2, y2);
-				pcb_line_new(&PCB->Data->Layer[0], PCB_MIL_TO_COORD(x1), PCB_MIL_TO_COORD(y1), PCB_MIL_TO_COORD(x2), PCB_MIL_TO_COORD(y2), PCB_MIL_TO_COORD(10), PCB_MIL_TO_COORD(10), pcb_flag_make(PCB_FLAG_AUTO));
+				pcb_line_new(CURRENT, PCB_MIL_TO_COORD(x1), PCB_MIL_TO_COORD(y1), PCB_MIL_TO_COORD(x2), PCB_MIL_TO_COORD(y2), PCB_MIL_TO_COORD(10), PCB_MIL_TO_COORD(10), pcb_flag_make(PCB_FLAG_AUTO));
 				x2 = x1;
 				y2 = y1;
 				break;