combine_path: Fixed corner case. combine_path() on strings starting with "./../" used to gain one directory level. Eg: Old behavior: > combine_path(".", "../foo"); (1) Result: "../foo" > combine_path("./..", "foo"); (2) Result: "foo" > combine_path("./../foo"); (3) Result: "foo" New (fixed) behavior: > combine_path(".", "../foo"); (1) Result: "../foo" > combine_path("./..", "foo"); (2) Result: "../foo" > combine_path("./../foo"); (3) Result: "../foo" Fixes PIKE-137 (#8137).