Crash on invalid regular expressions in misc:swallow_regex

[jbeich]

libc++ doesn't like [[EMPTY]] but otherwise both libc++ and libstdc++ will raise an exception (thus crash Hyprland) with something unambigously invalid.

$ Hyprland -c /tmp/hyprland.conf
[...]
terminate called after throwing an instance of 'std::regex_error'
  what():  Mismatched '(' and ')' in regular expression
Abort trap

(gdb) bt
#0  0x000000080125633a in thr_kill () at /lib/libc.so.7
#1  0x00000008011cec74 in raise () at /lib/libc.so.7
#2  0x0000000801280109 in abort () at /lib/libc.so.7
#3  0x000000000068b1f8 in __gnu_cxx::__verbose_terminate_handler() [clone .cold] ()
#4  0x0000000000900c56 in __cxxabiv1::__terminate(void (*)()) ()
#5  0x0000000000900cb1 in  ()
#6  0x0000000000900e1c in  ()
#7  0x000000000068cab0 in std::__throw_regex_error(std::regex_constants::error_type) ()
#8  0x00000000007422fc in std::__detail::_Compiler<std::__cxx11::regex_traits<char> >::_Compiler(char const*, char const*, std::locale const&, std::regex_constants::syntax_option_type) ()
#9  0x00000000007415c7 in std::__cxx11::basic_regex<char, std::__cxx11::regex_traits<char> >::_M_compile(char const*, char const*, std::regex_constants::syntax_option_type) ()
#10 0x0000000000740c95 in std::__cxx11::basic_regex<char, std::__cxx11::regex_traits<char> >::basic_regex<std::char_traits<char>, std::allocator<char> >(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::regex_constants::syntax_option_type) ()
#11 0x0000000000739d06 in Events::listener_mapWindow(void*, void*) ()
#12 0x00000000006ef2f1 in void std::__invoke_impl<void, void (*&)(void*, void*), void*, void*>(std::__invoke_other, void (*&)(void*, void*), void*&&, void*&&) ()
#13 0x00000000006ee037 in std::enable_if<is_invocable_r_v<void, void (*&)(void*, void*), void*, void*>, void>::type std::__invoke_r<void, void (*&)(void*, void*), void*, void*>(void (*&)(void*, void*), void*&&, void*&&) ()
#14 0x00000000006eceb5 in std::_Function_handler<void (void*, void*), void (*)(void*, void*)>::_M_invoke(std::_Any_data const&, void*&&, void*&&) ()
#15 0x000000000084b57f in std::function<void (void*, void*)>::operator()(void*, void*) const ()
#16 0x000000000084b385 in CHyprWLListener::emit(void*) ()
#17 0x000000000084afac in handleWrapped(wl_listener*, void*) ()
#18 0x0000000800bce4e4 in wl_signal_emit_mutable (signal=0x8026af7e0, data=0x0) at ../src/wayland-server.c:2241
#19 0x00000000008ac8f5 in xdg_surface_role_commit ()
#20 0x00000000008b0f90 in surface_commit_state ()
#21 0x00000000008b1060 in surface_handle_commit ()
#22 0x000000080154507a in ffi_call_unix64 () at ../src/x86/unix64.S:104
#23 0x000000080154486c in ffi_call_int
    (cif=0x7fffffffe2b0, fn=0x8b0fcf <surface_handle_commit>, rvalue=0x0, avalue=0x7fffffffe380, closure=0x0) at ../src/x86/ffi64.c:673
#24 0x0000000801544a0c in ffi_call (cif=0x7fffffffe2b0, fn=0x8b0fcf <surface_handle_commit>, rvalue=0x0, avalue=0x7fffffffe380)
    at ../src/x86/ffi64.c:710
#25 0x0000000800bd38f3 in wl_closure_invoke (closure=0x81071f7a0, flags=2, target=0x80dc74800, opcode=6, data=0x81071f420)
    at ../src/connection.c:1025
#26 0x0000000800bcbd43 in wl_client_connection_data (fd=33, mask=1, data=0x81071f420) at ../src/wayland-server.c:438
#27 0x0000000800bcf9ef in wl_event_source_fd_dispatch (source=0x80dc67a00, ep=0x7fffffffe530) at ../src/event-loop.c:112
#28 0x0000000800bd110a in wl_event_loop_dispatch (loop=0x8026393c0, timeout=-1) at ../src/event-loop.c:1027
#29 0x0000000800bcd515 in wl_display_run (display=0x80269f0e0) at ../src/wayland-server.c:1493
#30 0x00000000007b191c in CCompositor::startCompositor() ()
#31 0x0000000000712e3c in main ()

$ cat /tmp/hyprland.conf
exec-once = kitty

misc {
    enable_swallow = true
    swallow_regex = ?
    swallow_exception_regex = ?
}

Simplified example:

$ clang++ -o test-libc++ -stdlib=libc++ a.cc
$ g++ -o test-libstdc++ a.cc

$ ./test-libc++ "[[EMPTY]]"
regex_error: The parser did not consume the entire regular expression.
$ ./test-libc++ "?"
regex_error: One of *?+{ was not preceded by a valid regular expression.

$ ./test-libstdc++ "[[EMPTY]]"
$ ./test-libstdc++ "?"
regex_error: Mismatched '(' and ')' in regular expression

$ cat a.cc
#include <iostream>
#include <regex>

int main(int argc, char **argv)
{
    if (argc < 2) {
	std::cerr << "usage: " << argv[0] << " regex" << std::endl;
	return 1;
    }
    try {
        std::regex rgx(argv[1]);
    }
    catch (const std::regex_error& e) {
        std::cout << "regex_error: " << e.what() << std::endl;
    }
    return 0;
}

[vaxerski]

should be fixed with 8944db4