--TEST-- Bug #62759: Buggy grapheme_substr() on edge case --SKIPIF-- --FILE-- --EXPECT-- bool(false) string(0) "" bool(false) string(61) "grapheme_substr: invalid parameters: U_ILLEGAL_ARGUMENT_ERROR" string(0) "" bool(false) string(65) "grapheme_substr: length is beyond start: U_ILLEGAL_ARGUMENT_ERROR" string(0) ""