Panic with :has selector #65
Description
Minimal repro:
$ htmlq --version
htmlq 0.4.0
$ echo "<div><h1>h1</h1></div><div><p>p</p></div>" | htmlq 'div'
<div><h1>h1</h1></div>
<div><p>p</p></div>
$ echo "<div><h1>h1</h1></div><div><p>p</p></div>" | RUST_BACKTRACE=full htmlq 'div:has(h1)'
thread 'main' panicked at 'Failed to parse CSS selector: ()', src/main.rs:248:10
stack backtrace:
0: 0x10256fc98 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h26781f9bfbe134a6
1: 0x1025870c0 - core::fmt::write::h5aa0c05a9caf85df
2: 0x10255bf30 - std::io::Write::write_fmt::h018da2c8c873b16b
3: 0x1025646e8 - std::panicking::default_hook::{{closure}}::h0239cbf25cfa6d83
4: 0x10256439c - std::panicking::default_hook::ha0ef000a358742e2
5: 0x102564bf8 - std::panicking::rust_panic_with_hook::had5e29c8530a78b2
6: 0x10256ffa0 - std::panicking::begin_panic_handler::{{closure}}::h7852e5e8d2675e0d
7: 0x10256fdac - std::sys_common::backtrace::__rust_end_short_backtrace::hf05a8afc922cafbe
8: 0x1025647fc - _rust_begin_unwind
9: 0x102590aec - core::panicking::panic_fmt::h94866529fc2e06b8
10: 0x102590bdc - core::result::unwrap_failed::h41371c24818ab0e0
11: 0x1024e50e8 - htmlq::main::h04e4887fa86dbd1a
12: 0x1024e9984 - std::sys_common::backtrace::__rust_begin_short_backtrace::hd36bd2ff6dd7522d
13: 0x1024bb480 - std::rt::lang_start::{{closure}}::h9583fbf5a663487c
14: 0x10255b8cc - std::rt::lang_start_internal::he17012042c5b2b42
15: 0x1024e56e8 - _mainExpected output: <div><h1>h1</h1></div>
This was on macOS (ARM), but I could also reproduce it in Linux (x86). I don't have any other OS/arch to test on.