make EDBM_index_arrays's stay in memory, blender was allocating an array and filling it for verts/edges/faces on every redraw.

this may introduce bugs which I didn't catch, but they are very easy to identify in a debug build which has asserts to ensure the arrays are valid before use.

in my own test drawing ~98,304 quads - this gave an overall ~16% drawing speedup.

9 files changed, 131 insertions, 101 deletions

diff --git a/source/blender/editors/mesh/editface.c b/source/blender/editors/mesh/editface.c
index 8c0777b2426..05f2269c359 100644
--- a/source/blender/editors/mesh/editface.c
+++ b/source/blender/editors/mesh/editface.c
@@ -852,7 +852,7 @@ void ED_mesh_mirrtopo_init(Mesh *me, const int ob_mode, MirrTopoStore_t *mesh_to
 
 	if (em) {
 		if (skip_em_vert_array_init == FALSE) {
-			EDBM_index_arrays_init(em, BM_VERT);
+			EDBM_index_arrays_ensure(em, BM_VERT);
 		}
 	}
 
@@ -888,11 +888,6 @@ void ED_mesh_mirrtopo_init(Mesh *me, const int ob_mode, MirrTopoStore_t *mesh_to
 			last = a;
 		}
 	}
-	if (em) {
-		if (skip_em_vert_array_init == FALSE) {
-			EDBM_index_arrays_free(em);
-		}
-	}
 
 	MEM_freeN(topo_pairs);
 	topo_pairs = NULL;
diff --git a/source/blender/editors/mesh/editmesh_add.c b/source/blender/editors/mesh/editmesh_add.c
index 763c6c98a99..94ff32c5aed 100644
--- a/source/blender/editors/mesh/editmesh_add.c
+++ b/source/blender/editors/mesh/editmesh_add.c
@@ -90,7 +90,7 @@ static void make_prim_finish(bContext *C, Object *obedit, int *state, int enter_
 	EDBM_selectmode_flush_ex(em, SCE_SELECT_VERTEX);
 
 	/* only recalc editmode tessface if we are staying in editmode */
-	EDBM_update_generic(C, em, !exit_editmode);
+	EDBM_update_generic(C, em, !exit_editmode, TRUE);
 
 	/* userdef */
 	if (exit_editmode) {
diff --git a/source/blender/editors/mesh/editmesh_knife.c b/source/blender/editors/mesh/editmesh_knife.c
index b7b71be0df9..31415cf98d2 100644
--- a/source/blender/editors/mesh/editmesh_knife.c
+++ b/source/blender/editors/mesh/editmesh_knife.c
@@ -2841,7 +2841,7 @@ static void knifetool_finish(bContext *C, wmOperator *op)
 #endif
 
 	EDBM_mesh_normals_update(kcd->em);
-	EDBM_update_generic(C, kcd->em, TRUE);
+	EDBM_update_generic(C, kcd->em, TRUE, TRUE);
 }
 
 /* copied from paint_image.c */
diff --git a/source/blender/editors/mesh/editmesh_rip.c b/source/blender/editors/mesh/editmesh_rip.c
index 9b8f90bc7cf..01a2579520a 100644
--- a/source/blender/editors/mesh/editmesh_rip.c
+++ b/source/blender/editors/mesh/editmesh_rip.c
@@ -1044,7 +1044,7 @@ static int edbm_rip_invoke(bContext *C, wmOperator *op, wmEvent *event)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
diff --git a/source/blender/editors/mesh/editmesh_select.c b/source/blender/editors/mesh/editmesh_select.c
index a98345cacec..e3f918b66c9 100644
--- a/source/blender/editors/mesh/editmesh_select.c
+++ b/source/blender/editors/mesh/editmesh_select.c
@@ -725,7 +725,7 @@ static int similar_face_select_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	/* we succeeded */
 	return OPERATOR_FINISHED;
@@ -767,7 +767,7 @@ static int similar_edge_select_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	/* we succeeded */
 	return OPERATOR_FINISHED;
@@ -812,7 +812,7 @@ static int similar_vert_select_exec(bContext *C, wmOperator *op)
 
 	EDBM_selectmode_flush(em);
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	/* we succeeded */
 	return OPERATOR_FINISHED;
@@ -1487,7 +1487,7 @@ static int mouse_mesh_shortest_path_edge(bContext *C, ViewContext *vc)
 				break;
 		}
 		
-		EDBM_update_generic(C, em, FALSE);
+		EDBM_update_generic(C, em, FALSE, FALSE);
 
 		return TRUE;
 	}
@@ -1678,7 +1678,7 @@ static int mouse_mesh_shortest_path_face(bContext *C, ViewContext *vc)
 
 		BM_active_face_set(em->bm, f_dst);
 
-		EDBM_update_generic(C, em, FALSE);
+		EDBM_update_generic(C, em, FALSE, FALSE);
 
 		return TRUE;
 	}
@@ -2635,7 +2635,7 @@ static int edbm_select_nth_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
diff --git a/source/blender/editors/mesh/editmesh_slide.c b/source/blender/editors/mesh/editmesh_slide.c
index 4fbe9c2534f..d5ca2e928da 100644
--- a/source/blender/editors/mesh/editmesh_slide.c
+++ b/source/blender/editors/mesh/editmesh_slide.c
@@ -264,7 +264,7 @@ static void vtx_slide_confirm(bContext *C, wmOperator *op)
 	EDBM_selectmode_flush(em);
 	
 	/* NC_GEOM | ND_DATA & Retess */
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 	
 	ED_region_tag_redraw(vso->active_region);
 }
@@ -752,7 +752,7 @@ static int edbm_vertex_slide_exec_ex(bContext *C, wmOperator *op, const int do_u
 
 	if (do_update) {
 		/* Update Geometry */
-		EDBM_update_generic(C, em, TRUE);
+		EDBM_update_generic(C, em, TRUE, FALSE);
 	}
 
 	return OPERATOR_FINISHED;
diff --git a/source/blender/editors/mesh/editmesh_tools.c b/source/blender/editors/mesh/editmesh_tools.c
index ad1077156ba..41d5cedbc2c 100644
--- a/source/blender/editors/mesh/editmesh_tools.c
+++ b/source/blender/editors/mesh/editmesh_tools.c
@@ -112,7 +112,7 @@ static int edbm_subdivide_exec(bContext *C, wmOperator *op)
 	                   RNA_boolean_get(op->ptr, "quadtri"), TRUE, FALSE,
 	                   RNA_int_get(op->ptr, "seed"));
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -181,7 +181,7 @@ static int edbm_unsubdivide_exec(bContext *C, wmOperator *op)
 	}
 	EDBM_selectmode_flush(em);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -463,7 +463,7 @@ static int edbm_extrude_repeat_exec(bContext *C, wmOperator *op)
 	
 	EDBM_mesh_normals_update(em);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -585,7 +585,7 @@ static int edbm_extrude_region_exec(bContext *C, wmOperator *op)
 	 * done.*/
 	EDBM_mesh_normals_update(em);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 	
 	return OPERATOR_FINISHED;
 }
@@ -678,7 +678,7 @@ static int edbm_extrude_faces_exec(bContext *C, wmOperator *op)
 
 	edbm_extrude_discrete_faces(em, op, BM_ELEM_SELECT, nor);
 	
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 	
 	return OPERATOR_FINISHED;
 }
@@ -936,7 +936,7 @@ static int edbm_dupli_extrude_cursor_invoke(bContext *C, wmOperator *op, wmEvent
 	 * done. */
 	EDBM_mesh_normals_update(vc.em);
 
-	EDBM_update_generic(C, vc.em, TRUE);
+	EDBM_update_generic(C, vc.em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1001,7 +1001,7 @@ static int edbm_delete_exec(bContext *C, wmOperator *op)
 
 	EDBM_flag_disable_all(em, BM_ELEM_SELECT);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 	
 	return OPERATOR_FINISHED;
 }
@@ -1034,7 +1034,7 @@ static int edbm_collapse_edge_exec(bContext *C, wmOperator *op)
 	if (!EDBM_op_callf(em, op, "collapse edges=%he", BM_ELEM_SELECT))
 		return OPERATOR_CANCELLED;
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1062,7 +1062,7 @@ static int edbm_collapse_edge_loop_exec(bContext *C, wmOperator *op)
 	if (!EDBM_op_callf(em, op, "dissolve_edge_loop edges=%he", BM_ELEM_SELECT))
 		return OPERATOR_CANCELLED;
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1121,7 +1121,7 @@ static int edbm_add_edge_face_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 	
 	return OPERATOR_FINISHED;
 }
@@ -1176,7 +1176,7 @@ static int edbm_mark_seam(bContext *C, wmOperator *op)
 	}
 
 	ED_uvedit_live_unwrap(scene, obedit);
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1230,7 +1230,7 @@ static int edbm_mark_sharp(bContext *C, wmOperator *op)
 		}
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1272,7 +1272,7 @@ static int edbm_vert_connect(bContext *C, wmOperator *op)
 	else {
 		EDBM_selectmode_flush(em);  /* so newly created edges get the selection state from the vertex */
 
-		EDBM_update_generic(C, em, TRUE);
+		EDBM_update_generic(C, em, TRUE, TRUE);
 
 		return len ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 	}
@@ -1310,7 +1310,7 @@ static int edbm_edge_split_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 	
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return len ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
@@ -1349,7 +1349,7 @@ static int edbm_duplicate_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 	
 	return OPERATOR_FINISHED;
 }
@@ -1388,7 +1388,7 @@ static int edbm_flip_normals_exec(bContext *C, wmOperator *op)
 	if (!EDBM_op_callf(em, op, "reverse_faces faces=%hf", BM_ELEM_SELECT))
 		return OPERATOR_CANCELLED;
 	
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1469,7 +1469,7 @@ static int edbm_edge_rotate_selected_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1500,7 +1500,7 @@ static int edbm_hide_exec(bContext *C, wmOperator *op)
 	
 	EDBM_mesh_hide(em, RNA_boolean_get(op->ptr, "unselected"));
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1530,7 +1530,7 @@ static int edbm_reveal_exec(bContext *C, wmOperator *UNUSED(op))
 	
 	EDBM_mesh_reveal(em);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1563,7 +1563,7 @@ static int edbm_normals_make_consistent_exec(bContext *C, wmOperator *op)
 	if (RNA_boolean_get(op->ptr, "inside"))
 		EDBM_op_callf(em, op, "reverse_faces faces=%hf", BM_ELEM_SELECT);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1645,7 +1645,7 @@ static int edbm_do_smooth_vertex_exec(bContext *C, wmOperator *op)
 		EDBM_verts_mirror_cache_end(em);
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }	
@@ -1721,7 +1721,7 @@ static int edbm_do_smooth_laplacian_vertex_exec(bContext *C, wmOperator *op)
 		EDBM_verts_mirror_cache_end(em);
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1775,7 +1775,7 @@ static int edbm_faces_shade_smooth_exec(bContext *C, wmOperator *UNUSED(op))
 
 	mesh_set_smooth_faces(em, 1);
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1802,7 +1802,7 @@ static int edbm_faces_shade_flat_exec(bContext *C, wmOperator *UNUSED(op))
 
 	mesh_set_smooth_faces(em, 0);
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -1845,7 +1845,7 @@ static int edbm_rotate_uvs_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	/* we succeeded */
 	return OPERATOR_FINISHED;
@@ -1868,7 +1868,7 @@ static int edbm_reverse_uvs_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	/* we succeeded */
 	return OPERATOR_FINISHED;
@@ -1895,7 +1895,7 @@ static int edbm_rotate_colors_exec(bContext *C, wmOperator *op)
 	}
 
 	/* dependencies graph and notification stuff */
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	/* we succeeded */
 	return OPERATOR_FINISHED;
@@ -1919,7 +1919,7 @@ static int edbm_reverse_colors_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	/* we succeeded */
 	return OPERATOR_FINISHED;
@@ -2104,7 +2104,7 @@ static int edbm_merge_exec(bContext *C, wmOperator *op)
 	if (!status)
 		return OPERATOR_CANCELLED;
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -2221,7 +2221,7 @@ static int edbm_remove_doubles_exec(bContext *C, wmOperator *op)
 	count = totvert_orig - em->bm->totvert;
 	BKE_reportf(op->reports, RPT_INFO, "Removed %d vertices", count);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -2328,7 +2328,7 @@ static int edbm_select_vertex_path_exec(bContext *C, wmOperator *op)
 
 	EDBM_selectmode_flush(em);
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	/* we succeeded */
 	return OPERATOR_FINISHED;
@@ -2403,7 +2403,7 @@ static int edbm_shape_propagate_to_all_exec(bContext *C, wmOperator *op)
 
 	shape_propagate(em, op);
 
-	EDBM_update_generic(C, em, FALSE);
+	EDBM_update_generic(C, em, FALSE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -2474,7 +2474,7 @@ static int edbm_blend_from_shape_exec(bContext *C, wmOperator *op)
 		}
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -2665,7 +2665,7 @@ static int edbm_solidify_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -2990,7 +2990,7 @@ static int edbm_knife_cut_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -3232,7 +3232,7 @@ static int edbm_separate_exec(bContext *C, wmOperator *op)
 		else                BLI_assert(0);
 
 		if (retval) {
-			EDBM_update_generic(C, em, TRUE);
+			EDBM_update_generic(C, em, TRUE, TRUE);
 		}
 	}
 	else {
@@ -3332,7 +3332,7 @@ static int edbm_fill_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 	
 	return OPERATOR_FINISHED;
 
@@ -3361,7 +3361,7 @@ static int edbm_beautify_fill_exec(bContext *C, wmOperator *op)
 	if (!EDBM_op_callf(em, op, "beautify_fill faces=%hf", BM_ELEM_SELECT))
 		return OPERATOR_CANCELLED;
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 	
 	return OPERATOR_FINISHED;
 }
@@ -3392,7 +3392,7 @@ static int edbm_quads_convert_to_tris_exec(bContext *C, wmOperator *op)
 	if (!EDBM_op_callf(em, op, "triangulate faces=%hf use_beauty=%b", BM_ELEM_SELECT, use_beauty))
 		return OPERATOR_CANCELLED;
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -3433,7 +3433,7 @@ static int edbm_tris_convert_to_quads_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -3489,7 +3489,7 @@ static int edbm_dissolve_exec(bContext *C, wmOperator *op)
 			return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -3561,7 +3561,7 @@ static int edbm_dissolve_limited_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -3606,7 +3606,7 @@ static int edbm_split_exec(bContext *C, wmOperator *op)
 	/* Geometry has changed, need to recalc normals and looptris */
 	EDBM_mesh_normals_update(em);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -3665,7 +3665,7 @@ static int edbm_spin_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -3788,7 +3788,7 @@ static int edbm_screw_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, TRUE);
 
 	return OPERATOR_FINISHED;
 }
@@ -4603,7 +4603,7 @@ static int edbm_noise_exec(bContext *C, wmOperator *op)
 
 	EDBM_mesh_normals_update(em);
 
-	EDBM_update_generic(C, em, TRUE);
+	EDBM_update_generic(C, em, TRUE, FALSE);
 
 	return OPERATOR_FINISHED;
 }
@@ -4827,7 +4827,7 @@ static int edbm_bevel_calc(bContext *C, wmOperator *op)
 	
 	EDBM_mesh_normals_update(opdata->em);
 	
-	EDBM_update_generic(C, opdata->em, TRUE);
+	EDBM_update_generic(C, opdata->em, TRUE, TRUE);
 
 	return 1;
 }
@@ -4859,7 +4859,7 @@ static int edbm_bevel_cancel(bContext *C, wmOperator *op)
 	BevelData *opdata = op->customdata;
 	if (opdata->is_modal) {
 		EDBM_redo_state_free(&opdata->mesh_backup, opdata->em, TRUE);
-		EDBM_update_generic(C, opdata->em, FALSE);
+		EDBM_update_generic(C, opdata->em, FALSE, TRUE);
 	}
 
 	edbm_bevel_exit(C, op);
@@ -5140,7 +5140,7 @@ static int edbm_bridge_edge_loops_exec(bContext *C, wmOperator *op)
 
 	}
 	else {
-		EDBM_update_generic(C, em, TRUE);
+		EDBM_update_generic(C, em, TRUE, TRUE);
 		return OPERATOR_FINISHED;
 	}
 }
@@ -5263,7 +5263,7 @@ static int edbm_inset_cancel(bContext *C, wmOperator *op)
 	opdata = op->customdata;
 	if (opdata->is_modal) {
 		EDBM_redo_state_free(&opdata->backup, opdata->em, TRUE);
-		EDBM_update_generic(C, opdata->em, FALSE);
+		EDBM_update_generic(C, opdata->em, FALSE, TRUE);
 	}
 
 	edbm_inset_exit(C, op);
@@ -5318,7 +5318,7 @@ static int edbm_inset_calc(bContext *C, wmOperator *op)
 		return 0;
 	}
 	else {
-		EDBM_update_generic(C, em, TRUE);
+		EDBM_update_generic(C, em, TRUE, TRUE);
 		return 1;
 	}
 }
@@ -5581,7 +5581,7 @@ static int edbm_wireframe_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 	else {
-		EDBM_update_generic(C, em, TRUE);
+		EDBM_update_generic(C, em, TRUE, TRUE);
 		return OPERATOR_FINISHED;
 	}
 }
@@ -5671,7 +5671,7 @@ static int edbm_convex_hull_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 	else {
-		EDBM_update_generic(C, em, TRUE);
+		EDBM_update_generic(C, em, TRUE, TRUE);
 		EDBM_selectmode_flush(em);
 		return OPERATOR_FINISHED;
 	}
@@ -5726,7 +5726,7 @@ static int mesh_symmetrize_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 	else {
-		EDBM_update_generic(C, em, TRUE);
+		EDBM_update_generic(C, em, TRUE, TRUE);
 		EDBM_selectmode_flush(em);
 		return OPERATOR_FINISHED;
 	}
diff --git a/source/blender/editors/mesh/editmesh_utils.c b/source/blender/editors/mesh/editmesh_utils.c
index 7259559603a..61bce9f8d1e 100644
--- a/source/blender/editors/mesh/editmesh_utils.c
+++ b/source/blender/editors/mesh/editmesh_utils.c
@@ -391,11 +391,13 @@ void EDBM_mesh_free(BMEditMesh *em)
 	BMEdit_Free(em);
 }
 
-void EDBM_index_arrays_init(BMEditMesh *em, const char htype)
+
+void EDBM_index_arrays_ensure(BMEditMesh *em, const char htype)
 {
 	BLI_assert((htype & ~BM_ALL_NOLOOP) == 0);
 
-	EDBM_index_arrays_free(em);
+	/* in debug mode double check we didn't need to recalculate */
+	BLI_assert(EDBM_index_arrays_check(em) == TRUE);
 
 	if (htype & BM_VERT) {
 		em->vert_index = MEM_mallocN(sizeof(void **) * em->bm->totvert, "em->vert_index");
@@ -430,6 +432,16 @@ void EDBM_index_arrays_init(BMEditMesh *em, const char htype)
 	}
 }
 
+/* use EDBM_index_arrays_ensure where possible to avoid full rebuild */
+void EDBM_index_arrays_init(BMEditMesh *em, const char htype)
+{
+	BLI_assert((htype & ~BM_ALL_NOLOOP) == 0);
+
+	/* force recalc */
+	EDBM_index_arrays_free(em);
+	EDBM_index_arrays_ensure(em, htype);
+}
+
 void EDBM_index_arrays_free(BMEditMesh *em)
 {
 	if (em->vert_index) {
@@ -448,6 +460,42 @@ void EDBM_index_arrays_free(BMEditMesh *em)
 	}
 }
 
+/* debug check only - no need to optimize */
+#ifdef DEBUG
+int EDBM_index_arrays_check(BMEditMesh *em)
+{
+	BMIter iter;
+	BMElem *ele;
+	int i;
+
+	if (em->vert_index) {
+		BM_ITER_MESH_INDEX (ele, &iter, em->bm, BM_VERTS_OF_MESH, i) {
+			if (ele != (BMElem *)em->vert_index[i]) {
+				return FALSE;
+			}
+		}
+	}
+
+	if (em->edge_index) {
+		BM_ITER_MESH_INDEX (ele, &iter, em->bm, BM_EDGES_OF_MESH, i) {
+			if (ele != (BMElem *)em->edge_index[i]) {
+				return FALSE;
+			}
+		}
+	}
+
+	if (em->face_index) {
+		BM_ITER_MESH_INDEX (ele, &iter, em->bm, BM_FACES_OF_MESH, i) {
+			if (ele != (BMElem *)em->face_index[i]) {
+				return FALSE;
+			}
+		}
+	}
+
+	return TRUE;
+}
+#endif
+
 BMVert *EDBM_vert_at_index(BMEditMesh *em, int index)
 {
 	return em->vert_index && index < em->bm->totvert ? em->vert_index[index] : NULL;
@@ -634,7 +682,7 @@ void undo_push_mesh(bContext *C, const char *name)
 }
 
 /* write comment here */
-UvVertMap *EDBM_uv_vert_map_create(BMEditMesh *em, int selected, int do_face_idx_array, const float limit[2])
+UvVertMap *EDBM_uv_vert_map_create(BMEditMesh *em, int selected, const float limit[2])
 {
 	BMVert *ev;
 	BMFace *efa;
@@ -647,11 +695,8 @@ UvVertMap *EDBM_uv_vert_map_create(BMEditMesh *em, int selected, int do_face_idx
 	MLoopUV *luv;
 	unsigned int a;
 	int totverts, i, totuv;
-	
-	if (do_face_idx_array)
-		EDBM_index_arrays_init(em, BM_FACE);
 
-	BM_mesh_elem_index_ensure(em->bm, BM_VERT);
+	BM_mesh_elem_index_ensure(em->bm, BM_VERT | BM_FACE);
 	
 	totverts = em->bm->totvert;
 	totuv = 0;
@@ -663,14 +708,10 @@ UvVertMap *EDBM_uv_vert_map_create(BMEditMesh *em, int selected, int do_face_idx
 	}
 
 	if (totuv == 0) {
-		if (do_face_idx_array)
-			EDBM_index_arrays_free(em);
 		return NULL;
 	}
 	vmap = (UvVertMap *)MEM_callocN(sizeof(*vmap), "UvVertMap");
 	if (!vmap) {
-		if (do_face_idx_array)
-			EDBM_index_arrays_free(em);
 		return NULL;
 	}
 
@@ -679,8 +720,6 @@ UvVertMap *EDBM_uv_vert_map_create(BMEditMesh *em, int selected, int do_face_idx
 
 	if (!vmap->vert || !vmap->buf) {
 		BKE_mesh_uv_vert_map_free(vmap);
-		if (do_face_idx_array)
-			EDBM_index_arrays_free(em);
 		return NULL;
 	}
 	
@@ -757,10 +796,7 @@ UvVertMap *EDBM_uv_vert_map_create(BMEditMesh *em, int selected, int do_face_idx
 		vmap->vert[a] = newvlist;
 		a++;
 	}
-	
-	if (do_face_idx_array)
-		EDBM_index_arrays_free(em);
-	
+
 	return vmap;
 }
 
@@ -1105,10 +1141,7 @@ void EDBM_verts_mirror_cache_begin(BMEditMesh *em, const short use_select)
 		topo = 1;
 	}
 
-	if (!em->vert_index) {
-		EDBM_index_arrays_init(em, BM_VERT);
-		em->mirr_free_arrays = 1;
-	}
+	EDBM_index_arrays_ensure(em, BM_VERT);
 
 	if (!CustomData_get_layer_named(&bm->vdata, CD_PROP_INT, BM_CD_LAYER_ID)) {
 		BM_data_layer_add_named(bm, &bm->vdata, CD_PROP_INT, BM_CD_LAYER_ID);
@@ -1200,11 +1233,6 @@ void EDBM_verts_mirror_cache_clear(BMEditMesh *em, BMVert *v)
 
 void EDBM_verts_mirror_cache_end(BMEditMesh *em)
 {
-	if (em->mirr_free_arrays) {
-		MEM_freeN(em->vert_index);
-		em->vert_index = NULL;
-	}
-
 	em->mirror_cdlayer = -1;
 }
 
@@ -1309,7 +1337,8 @@ void EDBM_mesh_reveal(BMEditMesh *em)
 
 /* so many tools call these that we better make it a generic function.
  */
-void EDBM_update_generic(bContext *C, BMEditMesh *em, const short do_tessface)
+void EDBM_update_generic(bContext *C, BMEditMesh *em,
+                         const short do_tessface, const short is_destructive)
 {
 	Object *ob = em->ob;
 	/* order of calling isn't important */
@@ -1319,4 +1348,12 @@ void EDBM_update_generic(bContext *C, BMEditMesh *em, const short do_tessface)
 	if (do_tessface) {
 		BMEdit_RecalcTessellation(em);
 	}
+
+	if (is_destructive) {
+		EDBM_index_arrays_free(em);
+	}
+	else {
+		/* in debug mode double check we didn't need to recalculate */
+		BLI_assert(EDBM_index_arrays_check(em) == TRUE);
+	}
 }
diff --git a/source/blender/editors/mesh/mesh_navmesh.c b/source/blender/editors/mesh/mesh_navmesh.c
index bae2c6cde9d..21564d2d348 100644
--- a/source/blender/editors/mesh/mesh_navmesh.c
+++ b/source/blender/editors/mesh/mesh_navmesh.c
@@ -375,7 +375,7 @@ static Object *createRepresentation(bContext *C, struct recast_polyMesh *pmesh,
 			BM_vert_create(em->bm, co, NULL, 0);
 		}
 
-		EDBM_index_arrays_init(em, BM_VERT);
+		EDBM_index_arrays_ensure(em, BM_VERT);
 
 		/* create faces */
 		for (j = 0; j < trinum; j++) {
@@ -399,8 +399,6 @@ static Object *createRepresentation(bContext *C, struct recast_polyMesh *pmesh,
 			polygonIdx = (int *)CustomData_bmesh_get(&em->bm->pdata, newFace->head.data, CD_RECAST);
 			*polygonIdx = i + 1; /* add 1 to avoid zero idx */
 		}
-		
-		EDBM_index_arrays_free(em);
 	}
 
 	recast_destroyPolyMesh(pmesh);