diff --git a/source/blender/bmesh/bmesh_walkers.h b/source/blender/bmesh/bmesh_walkers.h
index 9ed17121920..b33e9935bf7 100644
--- a/source/blender/bmesh/bmesh_walkers.h
+++ b/source/blender/bmesh/bmesh_walkers.h
@@ -19,19 +19,29 @@ typedef struct BMWalker {
 	void *(*yield)(struct BMWalker *walker);
 	int structsize;
 	BMWOrder order;
+	int valid_mask;
+
+	/* runtime */
 	int layer;
 
 	BMesh *bm;
 	BLI_mempool *worklist;
 	ListBase states;
-	short restrictflag;
+
+	short mask_vert;
+	short mask_edge;
+	short mask_loop;
+	short mask_face;
+
 	GHash *visithash;
 	int depth;
 } BMWalker;
 
 /*initialize a walker.  searchmask restricts some (not all) walkers to
   elements with a specific tool flag set.  flags is specific to each walker.*/
-void BMW_Init(struct BMWalker *walker, BMesh *bm, int type, short searchmask, int layer);
+void BMW_Init(struct BMWalker *walker, BMesh *bm, int type,
+              short mask_vert, short mask_edge, short mask_loop, short mask_face,
+              int layer);
 void *BMW_Begin(BMWalker *walker, void *start);
 void *BMW_Step(struct BMWalker *walker);
 void BMW_End(struct BMWalker *walker);
@@ -86,6 +96,8 @@ enum {
 	BMW_ISLAND,
 	/*walk from a vertex to all connected vertices.*/
 	BMW_CONNECTED_VERTEX,
+	/* end of array index enum vals */
+
 	/*do not intitialze function pointers and struct size in BMW_Init*/
 	BMW_CUSTOM,
 	BMW_MAXWALKERS
diff --git a/source/blender/bmesh/intern/bmesh_walkers.c b/source/blender/bmesh/intern/bmesh_walkers.c
index adfe64c6dd9..a4f5f53fd68 100644
--- a/source/blender/bmesh/intern/bmesh_walkers.c
+++ b/source/blender/bmesh/intern/bmesh_walkers.c
@@ -83,18 +83,28 @@ void *BMW_Begin(BMWalker *walker, void *start)
  *
 */
 
-void BMW_Init(BMWalker *walker, BMesh *bm, int type, short searchmask, int layer)
+void BMW_Init(BMWalker *walker, BMesh *bm, int type,
+              short mask_vert, short mask_edge, short mask_loop, short mask_face,
+              int layer)
 {
 	memset(walker, 0, sizeof(BMWalker));
 
 	walker->layer = layer;
 	walker->bm = bm;
-	walker->restrictflag = searchmask;
+
+	walker->mask_vert = mask_vert;
+	walker->mask_edge = mask_edge;
+	walker->mask_loop = mask_loop;
+	walker->mask_face = mask_face;
+
 	walker->visithash = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, "bmesh walkers 1");
 	
 	if (type >= BMW_MAXWALKERS || type < 0) {
 		bmesh_error();
-		fprintf(stderr, "Invalid walker type in BMW_Init; type: %d, searchmask: %d, flag: %d\n", type, searchmask, layer);
+		fprintf(stderr,
+		        "Invalid walker type in BMW_Init; type: %d, "
+		        "searchmask: (v:%d,e:%d,l:%d,f:%d), flag: %d\n",
+		        type, mask_vert, mask_edge, mask_loop, mask_face, layer);
 	}
 	
 	if (type != BMW_CUSTOM) {
@@ -103,6 +113,15 @@ void BMW_Init(BMWalker *walker, BMesh *bm, int type, short searchmask, int layer
 		walker->step = bm_walker_types[type]->step;
 		walker->structsize = bm_walker_types[type]->structsize;
 		walker->order = bm_walker_types[type]->order;
+		walker->valid_mask = bm_walker_types[type]->valid_mask;
+
+		/* safety checks */
+		/* if this raises an error either the caller is wrong or
+		 * 'bm_walker_types' needs updating */
+		BLI_assert(mask_vert==0 || (walker->valid_mask & BM_VERT));
+		BLI_assert(mask_edge==0 || (walker->valid_mask & BM_EDGE));
+		BLI_assert(mask_loop==0 || (walker->valid_mask & BM_LOOP));
+		BLI_assert(mask_face==0 || (walker->valid_mask & BM_FACE));
 	}
 	
 	walker->worklist = BLI_mempool_create(walker->structsize, 100, 100, TRUE, FALSE);
diff --git a/source/blender/bmesh/intern/bmesh_walkers_impl.c b/source/blender/bmesh/intern/bmesh_walkers_impl.c
index 45b4e8c5ffd..69a2a3a794c 100644
--- a/source/blender/bmesh/intern/bmesh_walkers_impl.c
+++ b/source/blender/bmesh/intern/bmesh_walkers_impl.c
@@ -61,7 +61,7 @@ static void shellWalker_visitEdge(BMWalker *walker, BMEdge *e)
 		return;
 	}
 
-	if (walker->restrictflag && !BMO_TestFlag(walker->bm, e, walker->restrictflag)) {
+	if (walker->mask_edge && !BMO_TestFlag(walker->bm, e, walker->mask_edge)) {
 		return;
 	}
 
@@ -188,7 +188,7 @@ static void connectedVertexWalker_visitVertex(BMWalker *walker, BMVert *v)
 		/* already visited */
 		return;
 	}
-	if (walker->restrictflag && !BMO_TestFlag(walker->bm, v, walker->restrictflag)) {
+	if (walker->mask_vert && !BMO_TestFlag(walker->bm, v, walker->mask_vert)) {
 		/* not flagged for walk */
 		return;
 	}
@@ -296,7 +296,7 @@ static void *islandboundWalker_step(BMWalker *walker)
 			l = bmesh_radial_nextloop(l);
 			f = l->f;
 			e = l->e;
-			if(walker->restrictflag && !BMO_TestFlag(walker->bm, f, walker->restrictflag)){
+			if(walker->mask_face && !BMO_TestFlag(walker->bm, f, walker->mask_face)){
 				l = l->radial_next;
 				break;
 			}
@@ -337,7 +337,7 @@ static void islandWalker_begin(BMWalker *walker, void *data)
 {
 	islandWalker *iwalk = NULL;
 
-	if (walker->restrictflag && !BMO_TestFlag(walker->bm, data, walker->restrictflag)) {
+	if (walker->mask_face && !BMO_TestFlag(walker->bm, data, walker->mask_face)) {
 		return;
 	}
 
@@ -368,7 +368,7 @@ static void *islandWalker_step(BMWalker *walker)
 	for (; l; l=BMIter_Step(&liter)) {
 		f = BMIter_New(&iter, walker->bm, BM_FACES_OF_EDGE, l->e);
 		for (; f; f=BMIter_Step(&iter)) {
-			if (walker->restrictflag && !BMO_TestFlag(walker->bm, f, walker->restrictflag)) {
+			if (walker->mask_face && !BMO_TestFlag(walker->bm, f, walker->mask_face)) {
 				continue;
 			}
 			if (BLI_ghash_haskey(walker->visithash, f)) continue;
@@ -765,7 +765,7 @@ static void *uvedgeWalker_step(BMWalker *walker)
 
 	BMW_removestate(walker);
 	
-	if (walker->restrictflag && !BMO_TestFlag(walker->bm, l->e, walker->restrictflag))
+	if (walker->mask_edge && !BMO_TestFlag(walker->bm, l->e, walker->mask_edge))
 		return l;
 
 	/*go over loops around l->v and nl->v and see which ones share l and nl's 
@@ -780,7 +780,7 @@ static void *uvedgeWalker_step(BMWalker *walker)
 			for (j=0; j<rlen; j++) {
 				if (BLI_ghash_haskey(walker->visithash, l2))
 					continue;
-				if (walker->restrictflag && !(BMO_TestFlag(walker->bm, l2->e, walker->restrictflag)))
+				if (walker->mask_edge && !(BMO_TestFlag(walker->bm, l2->e, walker->mask_edge)))
 				{
 					if (l2->v != cl->v)
 						continue;
@@ -812,6 +812,7 @@ static BMWalker shell_walker_type = {
 	shellWalker_yield,
 	sizeof(shellWalker),
 	BMW_BREADTH_FIRST,
+	BM_EDGE, /* valid restrict masks */
 };
 
 static BMWalker islandbound_walker_type = {
@@ -820,6 +821,7 @@ static BMWalker islandbound_walker_type = {
 	islandboundWalker_yield,
 	sizeof(islandboundWalker),
 	BMW_DEPTH_FIRST,
+	BM_FACE, /* valid restrict masks */
 };
 
 static BMWalker island_walker_type = {
@@ -828,6 +830,7 @@ static BMWalker island_walker_type = {
 	islandWalker_yield,
 	sizeof(islandWalker),
 	BMW_BREADTH_FIRST,
+	BM_FACE, /* valid restrict masks */
 };
 
 static BMWalker loop_walker_type = {
@@ -836,6 +839,7 @@ static BMWalker loop_walker_type = {
 	loopWalker_yield,
 	sizeof(loopWalker),
 	BMW_DEPTH_FIRST,
+	0, /* valid restrict masks */ /* could add flags here but so far none are used */
 };
 
 static BMWalker faceloop_walker_type = {
@@ -844,6 +848,7 @@ static BMWalker faceloop_walker_type = {
 	faceloopWalker_yield,
 	sizeof(faceloopWalker),
 	BMW_DEPTH_FIRST,
+	0, /* valid restrict masks */ /* could add flags here but so far none are used */
 };
 
 static BMWalker edgering_walker_type = {
@@ -852,6 +857,7 @@ static BMWalker edgering_walker_type = {
 	edgeringWalker_yield,
 	sizeof(edgeringWalker),
 	BMW_DEPTH_FIRST,
+	0, /* valid restrict masks */ /* could add flags here but so far none are used */
 };
 
 static BMWalker loopdata_region_walker_type = {
@@ -860,6 +866,7 @@ static BMWalker loopdata_region_walker_type = {
 	uvedgeWalker_yield,
 	sizeof(uvedgeWalker),
 	BMW_DEPTH_FIRST,
+	BM_EDGE, /* valid restrict masks */
 };
 
 static BMWalker connected_vertex_walker_type = {
@@ -868,17 +875,18 @@ static BMWalker connected_vertex_walker_type = {
 	connectedVertexWalker_yield,
 	sizeof(connectedVertexWalker),
 	BMW_BREADTH_FIRST,
+	BM_VERT, /* valid restrict masks */
 };
 
 BMWalker *bm_walker_types[] = {
-	&shell_walker_type,
-	&loop_walker_type,
-	&faceloop_walker_type,
-	&edgering_walker_type,
-	&loopdata_region_walker_type,
-	&islandbound_walker_type,
-	&island_walker_type,
-	&connected_vertex_walker_type,
+	&shell_walker_type,              /* BMW_SHELL */
+	&loop_walker_type,               /* BMW_LOOP */
+	&faceloop_walker_type,           /* BMW_FACELOOP */
+	&edgering_walker_type,           /* BMW_EDGERING */
+	&loopdata_region_walker_type,    /* BMW_LOOPDATA_ISLAND */
+	&islandbound_walker_type,        /* BMW_ISLANDBOUND */
+	&island_walker_type,             /* BMW_ISLAND */
+	&connected_vertex_walker_type,   /* BMW_CONNECTED_VERTEX */
 };
 
 int bm_totwalkers = sizeof(bm_walker_types) / sizeof(*bm_walker_types);
diff --git a/source/blender/bmesh/operators/dissolveops.c b/source/blender/bmesh/operators/dissolveops.c
index 6e61956f6ef..a8f73da2d84 100644
--- a/source/blender/bmesh/operators/dissolveops.c
+++ b/source/blender/bmesh/operators/dissolveops.c
@@ -28,7 +28,7 @@ static int UNUSED_FUNCTION(check_hole_in_region)(BMesh *bm, BMFace *f)
 
 	/*checks if there are any unmarked boundary edges in the face region*/
 
-	BMW_Init(&regwalker, bm, BMW_ISLAND, FACE_MARK, BMW_NIL_LAY);
+	BMW_Init(&regwalker, bm, BMW_ISLAND,  0,0,0,FACE_MARK,  BMW_NIL_LAY);
 	f2 = BMW_Begin(&regwalker, f);
 	for (; f2; f2=BMW_Step(&regwalker)) {
 		l2 = BMIter_New(&liter2, bm, BM_LOOPS_OF_FACE, f2);
@@ -69,7 +69,7 @@ void dissolvefaces_exec(BMesh *bm, BMOperator *op)
 		faces = NULL; /*forces different allocation*/
 
 		/*yay, walk!*/
-		BMW_Init(&regwalker, bm, BMW_ISLAND, FACE_MARK, BMW_NIL_LAY);
+		BMW_Init(&regwalker, bm, BMW_ISLAND,  0,0,0,FACE_MARK,  BMW_NIL_LAY);
 		f2 = BMW_Begin(&regwalker, f);
 		for (; f2; f2=BMW_Step(&regwalker)) {
 			BLI_array_append(faces, f2);
diff --git a/source/blender/bmesh/operators/removedoubles.c b/source/blender/bmesh/operators/removedoubles.c
index c7a38c94c45..14d74a61e4c 100644
--- a/source/blender/bmesh/operators/removedoubles.c
+++ b/source/blender/bmesh/operators/removedoubles.c
@@ -347,7 +347,7 @@ void bmesh_collapse_exec(BMesh *bm, BMOperator *op)
 	BMO_Init_Op(bm, &weldop, "weldverts");
 
 	BMO_Flag_Buffer(bm, op, "edges", EDGE_MARK, BM_EDGE);	
-	BMW_Init(&walker, bm, BMW_SHELL, EDGE_MARK, BMW_NIL_LAY);
+	BMW_Init(&walker, bm, BMW_SHELL,  0,EDGE_MARK,0,0,  BMW_NIL_LAY);
 
 	BM_ITER(e, &iter, bm, BM_EDGES_OF_MESH, NULL) {
 		if (!BMO_TestFlag(bm, e, EDGE_MARK))
@@ -402,7 +402,7 @@ static void bmesh_collapsecon_do_layer(BMesh *bm, BMOperator *op, int layer)
 	BMO_Clear_Flag_All(bm, op, BM_ALL, 65535);
 
 	BMO_Flag_Buffer(bm, op, "edges", EDGE_MARK, BM_EDGE);
-	BMW_Init(&walker, bm, BMW_LOOPDATA_ISLAND, EDGE_MARK, layer);
+	BMW_Init(&walker, bm, BMW_LOOPDATA_ISLAND, 0,EDGE_MARK,0,0, layer);
 
 	BM_ITER(f, &iter, bm, BM_FACES_OF_MESH, NULL) {
 		BM_ITER(l, &liter, bm, BM_LOOPS_OF_FACE, f) {
diff --git a/source/blender/editors/mesh/bmesh_select.c b/source/blender/editors/mesh/bmesh_select.c
index d583f505a46..055c08ea6f3 100644
--- a/source/blender/editors/mesh/bmesh_select.c
+++ b/source/blender/editors/mesh/bmesh_select.c
@@ -885,7 +885,7 @@ static void walker_select(BMEditMesh *em, int walkercode, void *start, int selec
 	BMHeader *h;
 	BMWalker walker;
 
-	BMW_Init(&walker, bm, walkercode, 0, BMW_NIL_LAY);
+	BMW_Init(&walker, bm, walkercode, 0,0,0,0, BMW_NIL_LAY);
 	h = BMW_Begin(&walker, start);
 	for (; h; h=BMW_Step(&walker)) {
 		if (!select)
@@ -1770,7 +1770,7 @@ static int select_linked_pick_invoke(bContext *C, wmOperator *op, wmEvent *event
 		eed = eve->e;
 	}
 
-	BMW_Init(&walker, em->bm, BMW_SHELL, 0, BMW_NIL_LAY);
+	BMW_Init(&walker, em->bm, BMW_SHELL, 0,0,0,0, BMW_NIL_LAY);
 	e = BMW_Begin(&walker, eed->v1);
 	for (; e; e=BMW_Step(&walker)) {
 			BM_Select(em->bm, e->v1, sel);
@@ -1822,7 +1822,7 @@ static int select_linked_exec(bContext *C, wmOperator *UNUSED(op))
 		}
 	}
 
-	BMW_Init(&walker, em->bm, BMW_SHELL, 0, BMW_NIL_LAY);
+	BMW_Init(&walker, em->bm, BMW_SHELL, 0,0,0,0, BMW_NIL_LAY);
 	for (i=0; i<tot; i++) {
 		e = BMW_Begin(&walker, verts[i]);
 		for (; e; e=BMW_Step(&walker)) {
@@ -1942,6 +1942,7 @@ static void walker_deselect_nth(BMEditMesh *em, int nth, int offset, BMHeader *h
 	BMWalker walker;
 	BMIter iter;
 	int walktype = 0, itertype = 0, flushtype = 0;
+	short mask_vert=0, mask_edge=0, mask_loop=0, mask_face=0;
 
 	/* No active element from which to start - nothing to do */
 	if(h_act==NULL) {
@@ -1955,16 +1956,19 @@ static void walker_deselect_nth(BMEditMesh *em, int nth, int offset, BMHeader *h
 		itertype = BM_VERTS_OF_MESH;
 		walktype = BMW_CONNECTED_VERTEX;
 		flushtype = SCE_SELECT_VERTEX;
+		mask_vert = BM_SELECT;
 		break;
 	case BM_EDGE:
 		itertype = BM_EDGES_OF_MESH;
 		walktype = BMW_SHELL;
 		flushtype = SCE_SELECT_EDGE;
+		mask_edge = BM_SELECT;
 		break;
 	case BM_FACE:
 		itertype = BM_FACES_OF_MESH;
 		walktype = BMW_ISLAND;
 		flushtype = SCE_SELECT_FACE;
+		mask_face = BM_SELECT;
 		break;
 	}
 
@@ -1978,7 +1982,7 @@ static void walker_deselect_nth(BMEditMesh *em, int nth, int offset, BMHeader *h
 	}
 
 	/* Walk over selected elements starting at active */
-	BMW_Init(&walker, bm, walktype, BM_SELECT, BMW_NIL_LAY);
+	BMW_Init(&walker, bm, walktype,  mask_vert,mask_edge,mask_loop,mask_face,  BMW_NIL_LAY);
 	BLI_assert(walker.order == BMW_BREADTH_FIRST);
 	for (h = BMW_Begin(&walker, h_act); h != NULL; h = BMW_Step(&walker)) {
 		/* Deselect elements that aren't at "nth" depth from active */
diff --git a/source/blender/editors/mesh/bmesh_tools.c b/source/blender/editors/mesh/bmesh_tools.c
index 5cda6893131..090e01d701d 100644
--- a/source/blender/editors/mesh/bmesh_tools.c
+++ b/source/blender/editors/mesh/bmesh_tools.c
@@ -3330,7 +3330,7 @@ static int mesh_separate_loose(Main *bmain, Scene *scene, Base *editbase, wmOper
 
 		/*Walk from the single vertex, selecting everything connected
 		  to it*/
-		BMW_Init(&walker, bm, BMW_SHELL, 0, BMW_NIL_LAY);
+		BMW_Init(&walker, bm, BMW_SHELL,  0,0,0,0,  BMW_NIL_LAY);
 		e = BMW_Begin(&walker, v_seed);
 		for (; e; e=BMW_Step(&walker)) {
 			BM_Select(bm, e->v1, 1);
diff --git a/source/blender/editors/mesh/loopcut.c b/source/blender/editors/mesh/loopcut.c
index c3797962f0b..313ebb310de 100644
--- a/source/blender/editors/mesh/loopcut.c
+++ b/source/blender/editors/mesh/loopcut.c
@@ -204,7 +204,7 @@ static void edgering_sel(tringselOpData *lcd, int previewlines, int select)
 	}
 
 	if (select) {
-		BMW_Init(&walker, em->bm, BMW_EDGERING, 0, BMW_NIL_LAY);
+		BMW_Init(&walker, em->bm, BMW_EDGERING,  0,0,0,0,  BMW_NIL_LAY);
 		eed = BMW_Begin(&walker, startedge);
 		for (; eed; eed=BMW_Step(&walker)) {
 			BM_Select(em->bm, eed, 1);
@@ -214,7 +214,7 @@ static void edgering_sel(tringselOpData *lcd, int previewlines, int select)
 		return;
 	}
 
-	BMW_Init(&walker, em->bm, BMW_EDGERING, 0, BMW_NIL_LAY);
+	BMW_Init(&walker, em->bm, BMW_EDGERING,  0,0,0,0,  BMW_NIL_LAY);
 	eed = startedge = BMW_Begin(&walker, startedge);
 	lastv1 = NULL;
 	for (lasteed=NULL; eed; eed=BMW_Step(&walker)) {