Index: trunk/src/polygon.c
===================================================================
--- trunk/src/polygon.c	(revision 12412)
+++ trunk/src/polygon.c	(revision 12413)
@@ -829,6 +829,14 @@
 	return Subtract(np, p, pcb_true);
 }
 
+/* return the clearance polygon for a line */
+static pcb_polyarea_t *line_clearance_poly(pcb_cardinal_t layernum, pcb_board_t *pcb, pcb_line_t *line)
+{
+	if (line->thermal & PCB_THERMAL_ON)
+		return pcb_thermal_area_line(pcb, line, layernum);
+	return pcb_poly_from_line(line, line->Thickness + line->Clearance);
+}
+
 static int SubtractLine(pcb_line_t * line, pcb_poly_t * p)
 {
 	pcb_polyarea_t *np;
@@ -835,7 +843,7 @@
 
 	if (!PCB_NONPOLY_HAS_CLEARANCE(line))
 		return 0;
-	if (!(np = pcb_poly_from_line(line, line->Thickness + line->Clearance)))
+	if (!(np = line_clearance_poly(-1, NULL, line)))
 		return -1;
 	return Subtract(np, p, pcb_true);
 }
@@ -1126,7 +1134,8 @@
 		return PCB_R_DIR_NOT_FOUND;
 	polygon = info->polygon;
 
-	if (!(np = pcb_poly_from_line(line, line->Thickness + line->Clearance)))
+	np = line_clearance_poly(-1, NULL, line);
+	if (!np)
 		longjmp(info->env, 1);
 
 	pcb_polyarea_boolean_free(info->accumulate, np, &merged, PCB_PBO_UNITE);
Index: trunk/src/thermal.c
===================================================================
--- trunk/src/thermal.c	(revision 12412)
+++ trunk/src/thermal.c	(revision 12413)
@@ -145,7 +145,7 @@
 				}
 				else {
 					atmp.StartAngle = ea;
-					atmp.Delta = 100;
+					atmp.Delta = 360-ea+sa;
 				}
 				atmp.Width = atmp.Height = clrth;
 				pb = pcb_poly_from_arc(&atmp, clr);