Partial fix for bug 30695, "Array broke crease, weird visibility and slowdown"

* Array modifier creates BMesh from DM; add missing CD_CREASE layer
  for edge creases.

* With a modifier stack like mirror+subsurf+array, face normals were
  wrong. Fix by removing CD_NORMAL layer from CCGDM output. Previously
  the elements in this layer were simply copied, so they did not
  reflect subdivision correctly.

* Minor style fixes in bmo_dupe.c.

Issues not yet addressed:

* Subsurf's optimal draw setting for hiding subdivision edges is not
  respected by the array output.

* Slowdown issue; array modifier is much slower than in 2.62.

source/blender/blenkernel/intern/modifiers_bmesh.c

@@ -49,6 +49,7 @@ void DM_to_bmesh_ex(DerivedMesh *dm, BMesh *bm)
 	MLoop *mloop, *ml;
 	BMVert *v, **vtable, **verts = NULL;
 	BMEdge *e, **etable, **edges = NULL;
+	float has_face_normals;
 	BMFace *f;
 	BMIter liter;
 	BLI_array_declare(verts);
@@ -65,6 +66,9 @@ void DM_to_bmesh_ex(DerivedMesh *dm, BMesh *bm)
 	totedge = dm->getNumEdges(dm);
 	/* totface = dm->getNumPolys(dm); */ /* UNUSED */
 
+	/* add crease layer */
+	BM_data_layer_add(bm, &bm->edata, CD_CREASE);
+
 	vtable = MEM_callocN(sizeof(void**) * totvert, "vert table in BMDM_Copy");
 	etable = MEM_callocN(sizeof(void**) * totedge, "edge table in BMDM_Copy");
 
@@ -89,12 +93,16 @@ void DM_to_bmesh_ex(DerivedMesh *dm, BMesh *bm)
 
 		CustomData_to_bmesh_block(&dm->edgeData, &bm->edata, i, &e->head.data);
 		etable[i] = e;
+
+		/* add crease */
+		BM_elem_float_data_set(&bm->edata, e, CD_CREASE, (float)me->crease / 255.0f);
 	}
 	MEM_freeN(medge);
 
 	/*do faces*/
 	mp = dm->getPolyArray(dm);
 	mloop = dm->getLoopArray(dm);
+	has_face_normals = CustomData_has_layer(&dm->polyData, CD_NORMAL);
 	for (i = 0; i < dm->numPolyData; i++, mp++) {
 		BMLoop *l;
 
@@ -126,6 +134,13 @@ void DM_to_bmesh_ex(DerivedMesh *dm, BMesh *bm)
 		}
 
 		CustomData_to_bmesh_block(&dm->polyData, &bm->pdata, i, &f->head.data);
+
+		if (has_face_normals) {
+			float *fno;
+
+			fno = CustomData_bmesh_get(&bm->pdata, &f->head.data, CD_NORMAL);
+			copy_v3_v3(f->no, fno);
+		}
 	}
 
 	MEM_freeN(vtable);

source/blender/blenkernel/intern/subsurf_ccg.c

@@ -2945,6 +2945,9 @@ static CCGDerivedMesh *getCCGDerivedMesh(CCGSubSurf *ss,
 					 ccgSubSurf_getNumFinalFaces(ss)*4, 
 					 ccgSubSurf_getNumFinalFaces(ss));
 
+	CustomData_free_layer_active(&ccgdm->dm.polyData, CD_NORMAL,
+								 ccgdm->dm.numPolyData);
+	
 	numTex = CustomData_number_of_layers(&ccgdm->dm.loopData, CD_MLOOPUV);
 	numCol = CustomData_number_of_layers(&ccgdm->dm.loopData, CD_MLOOPCOL);
 	hasPCol = CustomData_has_layer(&ccgdm->dm.loopData, CD_PREVIEW_MLOOPCOL);

source/blender/bmesh/operators/bmo_dupe.c

@@ -202,32 +202,33 @@ static void copy_mesh(BMOperator *op, BMesh *source, BMesh *target)
 	vhash = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, "bmesh dupeops v");
 	ehash = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, "bmesh dupeops e");
 
+	/* duplicate flagged vertices */
 	for (v = BM_iter_new(&verts, source, BM_VERTS_OF_MESH, source); v; v = BM_iter_step(&verts)) {
 		if ( BMO_elem_flag_test(source, v, DUPE_INPUT) &&
 		    !BMO_elem_flag_test(source, v, DUPE_DONE))
 		{
 			BMIter iter;
-			int iso = 1;
+			int isolated = 1;
 
 			v2 = copy_vertex(source, v, target, vhash);
 
 			BM_ITER(f, &iter, source, BM_FACES_OF_VERT, v) {
 				if (BMO_elem_flag_test(source, f, DUPE_INPUT)) {
-					iso = 0;
+					isolated = 0;
 					break;
 				}
 			}
 
-			if (iso) {
+			if (isolated) {
 				BM_ITER(e, &iter, source, BM_EDGES_OF_VERT, v) {
 					if (BMO_elem_flag_test(source, e, DUPE_INPUT)) {
-						iso = 0;
+						isolated = 0;
 						break;
 					}
 				}
 			}
 
-			if (iso) {
+			if (isolated) {
 				BMO_slot_map_ptr_insert(source, op, "isovertmap", v, v2);
 			}