Index: thermal.c
===================================================================
--- thermal.c	(revision 12417)
+++ thermal.c	(revision 12418)
@@ -174,10 +174,64 @@
 					x2 + clrth * nx - clr * vx * 2.0, y2 + clrth * ny - clr * vy * 2.0,
 					clr, 180.0);
 				pcb_polyarea_boolean_free(pa, pb, &pc, PCB_PBO_UNITE);
+			}
+			else { /* non-diagonal */
+				/* split side lines */
+				pa = pa_line_at(
+					x1 - clrth * nx - clr * vx * 0.00, y1 - clrth * ny - clr * vy * 0.00,
+					mx - clrth * nx + clr * vx * 1.00, my - clrth * ny + clr * vy * 1.00,
+					clr);
+				pb = pa_line_at(
+					x1 + clrth * nx - clr * vx * 0.00, y1 + clrth * ny - clr * vy * 0.00,
+					mx + clrth * nx + clr * vx * 1.00, my + clrth * ny + clr * vy * 1.00,
+					clr);
+				pcb_polyarea_boolean_free(pa, pb, &pc, PCB_PBO_UNITE);
 
-				return pc;
+				pa = pc; pc = NULL;
+				pb = pa_line_at(
+					mx - clrth * nx - clr * vx * 1.00, my - clrth * ny - clr * vy * 1.00,
+					x2 - clrth * nx + clr * vx * 0.00, y2 - clrth * ny + clr * vy * 0.00,
+					clr);
+				pcb_polyarea_boolean_free(pa, pb, &pc, PCB_PBO_UNITE);
+
+				pa = pc; pc = NULL;
+				pb = pa_line_at(
+					mx + clrth * nx - clr * vx * 1.00, my + clrth * ny - clr * vy * 1.00,
+					x2 + clrth * nx + clr * vx * 0.00, y2 + clrth * ny + clr * vy * 0.00,
+					clr);
+				pcb_polyarea_boolean_free(pa, pb, &pc, PCB_PBO_UNITE);
+
+				/* split round cap, x1;y1 */
+				pa = pc; pc = NULL;
+				pb = pa_arc_at(x1, y1, clrth,
+					x1 - clrth * nx, y1 - clrth * ny,
+					x1 + clrth * vx - clr * nx, y1 + clrth * vy - clr * ny,
+					clr, 180.0);
+				pcb_polyarea_boolean_free(pa, pb, &pc, PCB_PBO_UNITE);
+
+				pa = pc; pc = NULL;
+				pb = pa_arc_at(x1, y1, clrth,
+					x1 + clrth * nx, y1 + clrth * ny,
+					x1 + clrth * vx + clr * nx, y1 + clrth * vy + clr * ny,
+					clr, 180.0);
+				pcb_polyarea_boolean_free(pa, pb, &pc, PCB_PBO_UNITE);
+
+				/* split round cap, x2;y2 */
+				pa = pc; pc = NULL;
+				pb = pa_arc_at(x2, y2, clrth,
+					x2 - clrth * nx, y2 - clrth * ny,
+					x2 - clrth * vx - clr * nx, y2 - clrth * vy - clr * ny,
+					clr, 180.0);
+				pcb_polyarea_boolean_free(pa, pb, &pc, PCB_PBO_UNITE);
+
+				pa = pc; pc = NULL;
+				pb = pa_arc_at(x2, y2, clrth,
+					x2 + clrth * nx, y2 + clrth * ny,
+					x2 - clrth * vx + clr * nx, y2 - clrth * vy + clr * ny,
+					clr, 180.0);
+				pcb_polyarea_boolean_free(pa, pb, &pc, PCB_PBO_UNITE);
 			}
-			
+			return pc;
 		case PCB_THERMAL_SHARP:
 			break;
 	}