Index: trunk/src/change.c
===================================================================
--- trunk/src/change.c	(revision 31210)
+++ trunk/src/change.c	(revision 31211)
@@ -38,6 +38,7 @@
 #include "draw.h"
 #include "select.h"
 #include "undo.h"
+#include "thermal.h"
 #include <librnd/core/actions.h>
 #include "obj_pstk_op.h"
 #include "obj_subc_parent.h"
@@ -126,12 +127,12 @@
 static pcb_opfunc_t ChangeThermalFunctions = {
 	NULL, /* common_pre */
 	NULL, /* common_post */
+	pcb_anyop_change_thermal, /* line */
 	NULL,
+	pcb_anyop_change_thermal, /* poly */
 	NULL,
 	NULL,
-	NULL,
-	NULL,
-	NULL,
+	NULL, /* arc */
 	NULL, /* gfx */
 	NULL,
 	NULL,
Index: trunk/src/obj_common.c
===================================================================
--- trunk/src/obj_common.c	(revision 31210)
+++ trunk/src/obj_common.c	(revision 31211)
@@ -448,3 +448,4 @@
 
 	return &obj->thermal;
 }
+
Index: trunk/src/thermal.c
===================================================================
--- trunk/src/thermal.c	(revision 31210)
+++ trunk/src/thermal.c	(revision 31211)
@@ -29,7 +29,11 @@
 #include "thermal.h"
 
 #include <librnd/core/compat_misc.h>
+#include <librnd/core/rnd_printf.h>
 #include "data.h"
+#include "draw.h"
+#include "undo.h"
+#include "obj_common.h"
 #include "obj_pstk.h"
 #include "obj_pstk_inlines.h"
 #include "obj_pinvia_therm.h"
@@ -36,6 +40,8 @@
 #include "polygon.h"
 #include "funchash_core.h"
 
+static const char core_thermal_cookie[] = "core/thermal.c";
+
 rnd_cardinal_t pcb_themal_style_new2old(unsigned char t)
 {
 	switch(t) {
@@ -859,3 +865,83 @@
 	return NULL;
 }
 
+
+/*** undoable thermal change ***/
+typedef struct {
+	pcb_board_t *pcb;
+	pcb_any_obj_t *obj;
+	unsigned char shape;
+} undo_anyobj_thermal_t;
+
+static int undo_anyobj_thermal_swap(void *udata)
+{
+	undo_anyobj_thermal_t *t = udata;
+	unsigned char old, *th = pcb_obj_common_get_thermal(t->obj, 0, 1);
+
+	if (th != NULL) {
+		pcb_poly_restore_to_poly(t->pcb->Data, t->obj->type, t->obj->parent.layer, t->obj);
+
+		old = *th;
+		*th = t->shape;
+		t->shape = old;
+
+		pcb_poly_clear_from_poly(t->pcb->Data, t->obj->type, t->obj->parent.layer, t->obj);
+		pcb_draw_invalidate(t->obj);
+	}
+	return 0;
+}
+
+static void undo_anyobj_thermal_print(void *udata, char *dst, size_t dst_len)
+{
+	undo_anyobj_thermal_t *t = udata;
+	rnd_snprintf(dst, dst_len, "anyobj_thermal: #%ld %d", t->obj->ID, t->shape);
+}
+
+static const uundo_oper_t undo_anyobj_thermal = {
+	core_thermal_cookie,
+	NULL, /* free */
+	undo_anyobj_thermal_swap,
+	undo_anyobj_thermal_swap,
+	undo_anyobj_thermal_print
+};
+
+
+int pcb_anyobj_set_thermal(pcb_any_obj_t *obj, unsigned char shape, int undoable)
+{
+	undo_anyobj_thermal_t *t;
+	pcb_board_t *pcb = NULL;
+
+	if (obj->type == PCB_OBJ_PSTK)
+		return -1; /* needs a layer */
+
+	if (undoable) {
+		assert(obj->parent_type == PCB_PARENT_LAYER);
+		pcb = pcb_data_get_top(obj->parent.layer->parent.data);
+	}
+
+	if (!undoable || (pcb == NULL)) {
+		unsigned char *th = pcb_obj_common_get_thermal(obj, 0, 1);
+		if (th != NULL)
+			*th = shape;
+		return 0;
+	}
+
+	t = pcb_undo_alloc(pcb, &undo_anyobj_thermal, sizeof(undo_anyobj_thermal_t));
+	t->pcb = pcb;
+	t->obj = obj;
+	t->shape = shape;
+	undo_anyobj_thermal_swap(t);
+	return 0;
+}
+
+void *pcb_anyop_change_thermal(pcb_opctx_t *ctx, pcb_any_obj_t *obj)
+{
+	if (PCB_FLAG_TEST(PCB_FLAG_LOCK, obj))
+		return NULL;
+
+	if (pcb_anyobj_set_thermal(obj, ctx->chgtherm.style, 1) != 0)
+		return NULL;
+
+	return obj;
+}
+
Index: trunk/src/thermal.h
===================================================================
--- trunk/src/thermal.h	(revision 31210)
+++ trunk/src/thermal.h	(revision 31211)
@@ -28,6 +28,7 @@
 #define PCB_THERMAL_H
 
 #include "obj_common.h"
+#include "operation.h"
 #include "layer.h"
 #include <librnd/poly/polygon1_gen.h>
 
@@ -62,5 +63,7 @@
 unsigned char pcb_themal_style_old2new(rnd_cardinal_t t);
 rnd_cardinal_t pcb_themal_style_new2old(unsigned char t);
 
+void *pcb_anyop_change_thermal(pcb_opctx_t *ctx, pcb_any_obj_t *ps);
 
+
 #endif