Infinite loop when parsing invalid file

[5225225]

#[test]
fn infinite_loop_invalid_file() {
    pdf::file::File::from_data(b"startxref%PDF-".as_ref()).unwrap();
}

This puts the decoder into an infinite loop, this test will never complete.

I found this by fuzzing, and the fuzzer says it was stuck in

==844227== ERROR: libFuzzer: timeout after 1 seconds
    #0 0x563a342640c1 in __sanitizer_print_stack_trace /rustc/llvm/src/llvm-project/compiler-rt/lib/asan/asan_stack.cpp:87:3
    #1 0x563a349b1158 in fuzzer::PrintStackTrace() (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0xa7c158)
    #2 0x563a3498b47c in fuzzer::Fuzzer::AlarmCallback() (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0xa5647c)
    #3 0x7efddb48686f  (/usr/lib/libpthread.so.0+0x1386f)
    #4 0x563a349b9804 in __sanitizer_cov_trace_const_cmp1 (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0xa84804)
    #5 0x563a34680d96 in pdf::parser::lexer::Lexer::next_word::hbd5751a146c5015e (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x74bd96)
    #6 0x563a3467f0d2 in pdf::parser::lexer::Lexer::next::h5e400b5eb1696032 (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x74a0d2)
    #7 0x563a342efdf6 in pdf::backend::Backend::locate_xref_offset::h5009a3aff8015953 (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x3badf6)
    #8 0x563a342f07c2 in pdf::backend::Backend::read_xref_table_and_trailer::h8690b18b8bcc1c0a (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x3bb7c2)
    #9 0x563a342cb3f6 in pdf::file::load_storage_and_trailer_password::h403607f8a77cc40c (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x3963f6)
    #10 0x563a342c9e7b in pdf::file::File$LT$B$GT$::load_data::h3c5cfdefdbfc04a8 (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x394e7b)
    #11 0x563a3449a5f4 in rust_fuzzer_test_input (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x5655f4)
    #12 0x563a34976818 in __rust_try (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0xa41818)
    #13 0x563a34975f7f in LLVMFuzzerTestOneInput (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0xa40f7f)
    #14 0x563a3498b771 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0xa56771)
    #15 0x563a3497f6aa in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0xa4a6aa)
    #16 0x563a349836c2 in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0xa4e6c2)
    #17 0x563a341df2e2 in main (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x2aa2e2)
    #18 0x7efddb181b24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
    #19 0x563a341df48d in _start (/home/jess/.cache/cargo/target/x86_64-unknown-linux-gnu/release/fuzz_target_1+0x2aa48d)

when it timed out