Index: trunk/src/change.c
===================================================================
--- trunk/src/change.c	(revision 31069)
+++ trunk/src/change.c	(revision 31070)
@@ -145,7 +145,7 @@
 	NULL, /* common_post */
 	pcb_lineop_change_clear_size,
 	NULL,
-	pcb_polyop_change_clear_size,				/* just to tell the user not to :-) */
+	pcb_polyop_change_clear_size,
 	NULL,
 	NULL,
 	pcb_arcop_change_clear_size,
@@ -157,6 +157,23 @@
 	0 /* extobj_inhibit_regen */
 };
 
+pcb_opfunc_t ChangeEnforceClearSizeFunctions = {
+	NULL, /* common_pre */
+	NULL, /* common_post */
+	NULL,
+	NULL,
+	pcb_polyop_change_enforce_clear_size,
+	NULL,
+	NULL,
+	NULL,
+	NULL, /* gfx */
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	0 /* extobj_inhibit_regen */
+};
+
 static pcb_opfunc_t ChangeNameFunctions = {
 	NULL, /* common_pre */
 	NULL, /* common_post */
@@ -653,6 +670,25 @@
 	return change;
 }
 
+rnd_bool pcb_chg_obj_enforce_clear_size(int Type, void *Ptr1, void *Ptr2, void *Ptr3, rnd_coord_t Difference, rnd_bool fixIt)
+{
+	rnd_bool change;
+	pcb_opctx_t ctx;
+
+	ctx.chgsize.pcb = PCB;
+	ctx.chgsize.is_primary = 1;
+	ctx.chgsize.is_absolute = fixIt;
+	ctx.chgsize.value = Difference;
+
+	change = (pcb_object_operation(&ChangeEnforceClearSizeFunctions, &ctx, Type, Ptr1, Ptr2, Ptr3) != NULL);
+	if (change) {
+		pcb_draw();
+		pcb_undo_inc_serial();
+	}
+	return change;
+}
+
+
 /* ---------------------------------------------------------------------------
  * changes the thermal of the passed object
  * Returns rnd_true if anything is changed
Index: trunk/src/change.h
===================================================================
--- trunk/src/change.h	(revision 31069)
+++ trunk/src/change.h	(revision 31070)
@@ -86,6 +86,7 @@
 rnd_bool pcb_chg_obj_1st_size(int, void *, void *, void *, rnd_coord_t, rnd_bool);
 rnd_bool pcb_chg_obj_thermal(int Type, void *Ptr1, void *Ptr2, void *Ptr3, int therm_type, unsigned long lid);
 rnd_bool pcb_chg_obj_clear_size(int, void *, void *, void *, rnd_coord_t, rnd_bool);
+rnd_bool pcb_chg_obj_enforce_clear_size(int Type, void *Ptr1, void *Ptr2, void *Ptr3, rnd_coord_t Difference, rnd_bool fixIt);
 rnd_bool pcb_chg_obj_2nd_size(int, void *, void *, void *, rnd_coord_t, rnd_bool, rnd_bool);
 rnd_bool pcb_chg_obj_rot(int, void *, void *, void *, double, rnd_bool, rnd_bool);
 rnd_bool pcb_chg_obj_join(int, void *, void *, void *);
Index: trunk/src/obj_poly.c
===================================================================
--- trunk/src/obj_poly.c	(revision 31069)
+++ trunk/src/obj_poly.c	(revision 31070)
@@ -716,6 +716,33 @@
 	return NULL;
 }
 
+/* Handle attempts to change the enforce_clearance of a polygon. */
+void *pcb_polyop_change_enforce_clear_size(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_poly_t *poly)
+{
+	rnd_coord_t value = (ctx->chgsize.is_absolute) ? ctx->chgsize.value : poly->Clearance + ctx->chgsize.value;
+
+	if (PCB_FLAG_TEST(PCB_FLAG_LOCK, poly))
+		return NULL;
+
+	if (!ctx->chgsize.is_absolute && ctx->chgsize.value < 0)
+		value = 0;
+	if (value != poly->enforce_clearance) {
+TODO("undo: enforce_clearance in poly");
+/*		pcb_undo_add_obj_to_clear_size(PCB_OBJ_POLY, Layer, poly, poly);*/
+		pcb_poly_restore_to_poly(ctx->chgsize.pcb->Data, PCB_OBJ_POLY, Layer, poly);
+		pcb_poly_invalidate_erase(poly);
+		rnd_r_delete_entry(Layer->polygon_tree, (rnd_rnd_box_t *)poly);
+		poly->enforce_clearance = value;
+		pcb_poly_bbox(poly);
+		rnd_r_insert_entry(Layer->polygon_tree, (rnd_rnd_box_t *)poly);
+		pcb_poly_clear_from_poly(ctx->chgsize.pcb->Data, PCB_OBJ_POLY, Layer, poly);
+		pcb_poly_invalidate_draw(Layer, poly);
+		return poly;
+	}
+
+	return poly;
+}
+
 /* changes the CLEARPOLY flag of a polygon */
 void *pcb_polyop_change_clear(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_poly_t *Polygon)
 {
Index: trunk/src/obj_poly_op.h
===================================================================
--- trunk/src/obj_poly_op.h	(revision 31069)
+++ trunk/src/obj_poly_op.h	(revision 31070)
@@ -33,6 +33,7 @@
 void *pcb_polyop_add_to_buffer(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_poly_t *Polygon);
 void *pcb_polyop_move_buffer(pcb_opctx_t *ctx, pcb_layer_t * layer, pcb_poly_t * polygon);
 void *pcb_polyop_change_clear_size(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_poly_t *poly);
+void *pcb_polyop_change_enforce_clear_size(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_poly_t *poly);
 void *pcb_polyop_change_clear(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_poly_t *Polygon);
 void *pcb_polyop_insert_point(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_poly_t *Polygon);
 void *pcb_polyop_move(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_poly_t *Polygon);