correct error in recent commit triangle-fill-dissolve, need to check if the edges face is removed (happens in rare cases).

source/blender/bmesh/operators/bmo_triangulate.c

@@ -137,6 +137,7 @@ void bmo_triangle_fill_exec(BMesh *bm, BMOperator *op)
 
 	if (use_dissolve) {
 		BMO_ITER (e, &siter, op->slots_out, "geom.out", BM_EDGE) {
+			if (LIKELY(e->l)) {  /* in rare cases the edges face will have already been removed from the edge */
 				BMFace *f_new;
 				f_new = BM_faces_join_pair(bm, e->l->f,
 				                           e->l->radial_next->f, e,
@@ -149,6 +150,10 @@ void bmo_triangle_fill_exec(BMesh *bm, BMOperator *op)
 					BMO_error_clear(bm);
 				}
 			}
+			else {
+				BM_edge_kill(bm, e);
+			}
+		}
 
 		BMO_slot_buffer_from_enabled_flag(bm, op, op->slots_out, "geom.out", BM_EDGE | BM_FACE, ELE_NEW);
 	}