diff --git a/source/blender/bmesh/bmesh.h b/source/blender/bmesh/bmesh.h
index 70a0820bece..7936df87c61 100644
--- a/source/blender/bmesh/bmesh.h
+++ b/source/blender/bmesh/bmesh.h
@@ -87,14 +87,14 @@ struct EditMesh;
  *
 */
 
-/*BMHeader->type*/
+/*BMHeader->htype (char) */
 #define BM_VERT 	1
 #define BM_EDGE 	2
 #define BM_LOOP 	4
 #define BM_FACE 	8
 #define BM_ALL		(BM_VERT | BM_EDGE | BM_LOOP | BM_FACE)
 
-/*BMHeader->flag*/
+/*BMHeader->hflag (char, all bits used!) */
 #define BM_SELECT	(1<<0)
 
 #define BM_SEAM		(1<<1)
@@ -305,6 +305,8 @@ void BM_Kill_Face_Verts(BMesh *bm, BMFace *f) ;
 /*clear all data in bm*/
 void BM_Clear_Mesh(BMesh *bm);
 
+void BM_ElemIndex_Ensure(BMesh *bm, const char hflag);
+
 /*start/stop edit*/
 void bmesh_begin_edit(struct BMesh *bm, int flag);
 void bmesh_end_edit(struct BMesh *bm, int flag);
diff --git a/source/blender/bmesh/intern/bmesh_mesh.c b/source/blender/bmesh/intern/bmesh_mesh.c
index cd75c301358..8821faf9106 100644
--- a/source/blender/bmesh/intern/bmesh_mesh.c
+++ b/source/blender/bmesh/intern/bmesh_mesh.c
@@ -481,3 +481,36 @@ void bmesh_end_edit(BMesh *bm, int flag)
 	BM_Compute_Normals(bm);
 	BM_SelectMode_Flush(bm);
 }
+
+void BM_ElemIndex_Ensure(BMesh *bm, const char hflag)
+{
+	BMIter iter;
+	BMHeader *ele;
+	int index;
+
+	/* TODO, mark arrays as dirty, only calculate if needed! */
+
+	if (hflag & BM_VERT) {
+		index= 0;
+		BM_ITER(ele, &iter, bm, BM_VERTS_OF_MESH, NULL) {
+			BM_SetIndex(ele, index);
+			index++;
+		}
+	}
+
+	if (hflag & BM_EDGE) {
+		index= 0;
+		BM_ITER(ele, &iter, bm, BM_EDGES_OF_MESH, NULL) {
+			BM_SetIndex(ele, index);
+			index++;
+		}
+	}
+
+	if (hflag & BM_FACE) {
+		index= 0;
+		BM_ITER(ele, &iter, bm, BM_FACES_OF_MESH, NULL) {
+			BM_SetIndex(ele, index);
+			index++;
+		}
+	}
+}
diff --git a/source/blender/bmesh/intern/bmesh_newcore.c b/source/blender/bmesh/intern/bmesh_newcore.c
index 2171ab2edea..f15b5a4a2fa 100644
--- a/source/blender/bmesh/intern/bmesh_newcore.c
+++ b/source/blender/bmesh/intern/bmesh_newcore.c
@@ -22,7 +22,9 @@
 BMVert *BM_Make_Vert(BMesh *bm, float co[3], const struct BMVert *example)
 {
 	BMVert *v = BLI_mempool_calloc(bm->vpool);
-	
+
+	BM_SetIndex(v, bm->totvert);
+
 	bm->totvert += 1;
 
 	v->head.htype = BM_VERT;
@@ -76,7 +78,11 @@ BMEdge *BM_Make_Edge(BMesh *bm, BMVert *v1, BMVert *v2, const BMEdge *example, i
 		return (BMEdge*)e;
 	
 	e = BLI_mempool_calloc(bm->epool);
+
+	BM_SetIndex(e, bm->totedge);
+
 	bm->totedge += 1;
+
 	e->head.htype = BM_EDGE;
 	
 	/*allocate flags*/
@@ -221,7 +227,11 @@ BMFace *BM_Make_Face(BMesh *bm, BMVert **verts, BMEdge **edges, int len, int nod
 	}
 	
 	f = BLI_mempool_calloc(bm->fpool);
+
+	BM_SetIndex(f, bm->totface);
+
 	bm->totface += 1;
+
 	f->head.htype = BM_FACE;
 
 	startl = lastl = BM_Add_FaceBoundary(bm, (BMFace*)f, verts[0], edges[0]);
diff --git a/source/blender/bmesh/intern/bmesh_operators.c b/source/blender/bmesh/intern/bmesh_operators.c
index 8e3229ea2b5..b78e71a51b1 100644
--- a/source/blender/bmesh/intern/bmesh_operators.c
+++ b/source/blender/bmesh/intern/bmesh_operators.c
@@ -1254,7 +1254,7 @@ int BMO_VInitOpf(BMesh *bm, BMOperator *op, const char *_fmt, va_list vlist)
 				state = 1;
 				break;
 			default:
-				printf("unrecognized bmop format char: %c\n", *fmt);
+				printf("%s: unrecognized bmop format char: %c\n", __func__, *fmt);
 				break;
 			}
 		}
@@ -1275,7 +1275,7 @@ int BMO_InitOpf(BMesh *bm, BMOperator *op, const char *fmt, ...)
 
 	va_start(list, fmt);
 	if (!BMO_VInitOpf(bm, op, fmt, list)) {
-		printf("BMO_InitOpf failed\n");
+		printf("%s: failed\n", __func__);
 		va_end(list);
 		return 0;
 	}
@@ -1291,7 +1291,7 @@ int BMO_CallOpf(BMesh *bm, const char *fmt, ...)
 
 	va_start(list, fmt);
 	if (!BMO_VInitOpf(bm, &op, fmt, list)) {
-		printf("BMO_CallOpf failed, format is:\n    \"%s\"\n", fmt);
+		printf("%s: failed, format is:\n    \"%s\"\n", __func__, fmt);
 		va_end(list);
 		return 0;
 	}
diff --git a/source/blender/editors/mesh/knifetool.c b/source/blender/editors/mesh/knifetool.c
index 1fd3366ecd5..511c41ff9ee 100755
--- a/source/blender/editors/mesh/knifetool.c
+++ b/source/blender/editors/mesh/knifetool.c
@@ -1147,8 +1147,8 @@ static KnifeEdge *knife_find_closest_edge(knifetool_opdata *kcd, float p[3], flo
 		if (cure && p) {
 			if (!kcd->ignore_edge_snapping || !(cure->e)) {
 				if (kcd->snap_midpoints) {
-					interp_v3_v3v3(p, cure->v1->co, cure->v2->co, 0.5f);
-					interp_v3_v3v3(cagep, cure->v1->cageco, cure->v2->cageco, 0.5f);
+					mid_v3_v3v3(p, cure->v1->co, cure->v2->co);
+					mid_v3_v3v3(cagep, cure->v1->cageco, cure->v2->cageco);
 				} else {
 					float d;