Segmentation fault in check_meshing_chords()

[jostle]

% The following source causes a segmentation fault

% in versions 2.20.0 and a local build from the latest master (2.23.1)

\version "2.20.0"
\language "english"

<< { a2  b2 } \\ { \tweak X-offset #2 f'1 ~ f'1 } >>

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Call stack from 2.23.1 is

(gdb) where
#0  0x000055b7a97836bb in check_meshing_chords(Grob*, Grob*, Grob*) (me=0x55b7aa7f80c0, 
clash_up=<optimised out>, clash_down=<optimised out>)
    at /usr/include/c++/10/bits/stl_vector.h:1043
#1  0x000055b7a978573e in check_meshing_chords(Grob*, Grob*, Grob*) 
(clash_down=0x55b7aa7f74c0, clash_up=0x55b7aa7f6dc0, me=0x55b7aa7f80c0)
    at /home/john/src/gitlab/lilypond/lily/note-collision.cc:47
#2  Note_collision_interface::automatic_shift(Grob*, Drul_array<std::vector<Grob*, 
std::allocator<Grob*> > >)
    (me=me@entry=0x55b7aa7f80c0, clash_groups=...) at 
/home/john/src/gitlab/lilypond/lily/note-collision.cc:489
#3  0x000055b7a9786357 in 
Note_collision_interface::calc_positioning_done(scm_unused_struct*) 
(smob=<optimised out>)
    at /home/john/src/gitlab/lilypond/build/../flower/include/drul-array.hh:30
#4  0x00007f75f24f306d in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#5  0x00007f75f24f8d5d in scm_call_n () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#6  0x00007f75f2475d0c in scm_call_1 () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#7  0x000055b7a9718435 in Grob::try_callback_on_alist(scm_unused_struct**, 
scm_unused_struct*, scm_unused_struct*)
    (this=this@entry=0x55b7aa7f80c0, alist=alist@entry=0x55b7aa7f8148, 
sym=0x7f75ee741b00, proc=0x7f75ee650840)
    at /home/john/src/gitlab/lilypond/lily/include/smobs.hh:321
#8  0x000055b7a971871f in Grob::internal_get_property(scm_unused_struct*) const 
(this=this@entry=0x55b7aa7f80c0, sym=<optimised out>)
    at /home/john/src/gitlab/lilypond/lily/grob-property.cc:203
#9  0x000055b7a971c33b in Grob::x_parent_positioning(scm_unused_struct*) 
(smob=<optimised out>) at /home/john/src/gitlab/lilypond/lily/grob.cc:865
#10 0x00007f75f24f306d in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#11 0x00007f75f24f8d5d in scm_call_n () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#12 0x00007f75f2475d0c in scm_call_1 () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#13 0x000055b7a9718435 in Grob::try_callback_on_alist(scm_unused_struct**, 
scm_unused_struct*, scm_unused_struct*)
    (this=this@entry=0x55b7aa7f6dc0, alist=alist@entry=0x55b7aa7f6e48, 
sym=sym@entry=0x7f75ee69b7e0, proc=0x7f75ee6930e0)
    at /home/john/src/gitlab/lilypond/lily/include/smobs.hh:321
#14 0x000055b7a971871f in Grob::internal_get_property(scm_unused_struct*) const 
(this=this@entry=0x55b7aa7f6dc0, sym=sym@entry=0x7f75ee69b7e0)
    at /home/john/src/gitlab/lilypond/lily/grob-property.cc:203
#15 0x000055b7a971da5b in Grob::get_offset(Axis) const 
(this=this@entry=0x55b7aa7f6dc0, a=a@entry=X_AXIS)
    at /home/john/src/gitlab/lilypond/lily/include/lily-guile-macros.hh:64
#16 0x000055b7a971e2be in Grob::relative_coordinate(Grob const*, Axis) const 
(a=X_AXIS, refp=0x55b7aa3bc1e0, this=0x55b7aa7f6dc0)
    at /home/john/src/gitlab/lilypond/lily/grob.cc:338
#17 Grob::relative_coordinate(Grob const*, Axis) const (a=X_AXIS, 
refp=0x55b7aa3bc1e0, this=0x55b7aa7f6dc0)
    at /home/john/src/gitlab/lilypond/lily/grob.cc:329
#18 Grob::parent_relative(Grob const*, Axis) const (a=X_AXIS, 
refp=0x55b7aa3bc1e0, this=0x55b7aa3a3d10)
    at /home/john/src/gitlab/lilypond/lily/grob.cc:345
#19 Grob::relative_coordinate(Grob const*, Axis) const (a=X_AXIS, 
refp=0x55b7aa3bc1e0, this=0x55b7aa3a3d10)
    at /home/john/src/gitlab/lilypond/lily/grob.cc:338
#20 Grob::relative_coordinate(Grob const*, Axis) const (a=X_AXIS, 
refp=0x55b7aa3bc1e0, this=0x55b7aa3a3d10)
    at /home/john/src/gitlab/lilypond/lily/grob.cc:329
#21 Grob::extent(Grob const*, Axis) const (this=this@entry=0x55b7aa3a3d10, 
refp=refp@entry=0x55b7aa3bc1e0, a=a@entry=X_AXIS)
    at /home/john/src/gitlab/lilypond/lily/grob.cc:455
#22 0x000055b7a9737981 in Ledger_line_spanner::set_spacing_rods(scm_unused_struct*) 
(smob=<optimised out>)
    at /home/john/src/gitlab/lilypond/lily/ledger-line-spanner.cc:129
#23 0x00007f75f24f306d in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#24 0x00007f75f24f8d5d in scm_call_n () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#25 0x00007f75f2475d0c in scm_call_1 () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#26 0x000055b7a9718435 in Grob::try_callback_on_alist(scm_unused_struct**, 
scm_unused_struct*, scm_unused_struct*)
    (this=this@entry=0x55b7aa3a56d0, alist=alist@entry=0x55b7aa3a5758, 
sym=0x7f75ee6941a0, proc=0x7f75ee67e680)
    at /home/john/src/gitlab/lilypond/lily/include/smobs.hh:321
#27 0x000055b7a971871f in Grob::internal_get_property(scm_unused_struct*) const 
(this=this@entry=0x55b7aa3a56d0, sym=<optimised out>)
    at /home/john/src/gitlab/lilypond/lily/grob-property.cc:203
#28 0x000055b7a9887aa3 in System::pre_processing() (this=0x55b7aa746400) at 
/home/john/src/gitlab/lilypond/lily/system.cc:548
#29 0x000055b7a970acf4 in ly_format_output(scm_unused_struct*) 
(context=context@entry=0x7f75f0865a40)
    at /home/john/src/gitlab/lilypond/lily/global-context-scheme.cc:40
#30 0x000055b7a98129ad in Score::book_rendering(Output_def*, Output_def*) 
(this=0x55b7aa7cfd10, layoutbook=0x55b7aa7cfda0, default_def=0x55b7aa4bb3c0)
    at /home/john/src/gitlab/lilypond/lily/score.cc:140
#31 0x000055b7a9691aff in Book::process_score(scm_unused_struct*, Paper_book*, 
Output_def*)
    (this=this@entry=0x55b7aa7cfd60, s=s@entry=0x7f75f0939680, 
output_paper_book=output_paper_book@entry=0x55b7aa7b82b0, 
layout=layout@entry=0x55b7aa4bb3c0) at 
/home/john/src/gitlab/lilypond/lily/book.cc:224
#32 0x000055b7a9692901 in Book::process(Output_def*, Output_def*, Paper_book*)
    (this=0x55b7aa7cfd60, default_paper=<optimised out>, 
default_layout=0x55b7aa4bb3c0, parent_part=parent_part@entry=0x0)
    at /home/john/src/gitlab/lilypond/lily/book.cc:307
#33 0x000055b7a969298b in Book::process(Output_def*, Output_def*)
    (this=<optimised out>, default_paper=<optimised out>, 
default_layout=<optimised out>) at /home/john/src/gitlab/lilypond/lily/book.cc:196
#34 0x000055b7a969020a in ly_book_process(scm_unused_struct*, 
scm_unused_struct*, scm_unused_struct*, scm_unused_struct*)
    (book_smob=<optimised out>, default_paper=<optimised out>, 
default_layout=<optimised out>, output=0x7f75f096df60)
    at /home/john/src/gitlab/lilypond/lily/book-scheme.cc:71
#35 0x00007f75f24f306d in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#36 0x00007f75f24f8d5d in scm_call_n () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#37 0x00007f75f2476f3b in scm_primitive_eval () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#38 0x00007f75f2480905 in scm_c_with_fluid () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#39 0x000055b7a97da743 in evaluate_embedded_scheme(scm_unused_struct*, Input 
const&, bool, Lily_parser*)
    (form=0x7f75f08e6210, start=..., safe=<optimised out>, parser=<optimised 
out>) at /home/john/src/gitlab/lilypond/lily/include/lily-modules.hh:65
#40 0x000055b7a98d59dd in Lily_lexer::eval_scm(scm_unused_struct*, Input, char) 
(this=this@entry=0x55b7aa3bf870, readerdata=<optimised out>,
    readerdata@entry=0x7f75f08e6210, location=..., 
extra_token=extra_token@entry=35 '#') at 
/home/john/src/gitlab/lilypond/lily/lexer.ll:1109
#41 0x000055b7a98dfcc7 in Lily_lexer::eval_scm_token(scm_unused_struct*, Input) 
(w=..., sval=0x7f75f08e6210, this=0x55b7aa3bf870)
    at /home/john/src/gitlab/lilypond/lily/include/lily-lexer.hh:58
#42 yyparse(Lily_parser*, scm_unused_struct**) (parser=<optimised out>, 
retval=<optimised out>) at /home/john/src/gitlab/lilypond/lily/parser.yy:448
#43 0x000055b7a98f4238 in Lily_parser::do_yyparse_trampoline(void*) 
(parser=<optimised out>) at /home/john/src/gitlab/lilypond/lily/parser.yy:4255
#44 0x00007f75f2480905 in scm_c_with_fluid () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#45 0x000055b7a98db5a2 in Lily_parser::do_yyparse() (this=<optimised out>) at 
/home/john/src/gitlab/lilypond/lily/include/lily-modules.hh:65
#46 0x000055b7a9745608 in Lily_parser::parse_file(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, 
std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, 
std::allocator<char> > const&) (this=this@entry=0x55b7aa7161e0, init="init.ly", name="coredump.ly", out_name="coredump")
    at /home/john/src/gitlab/lilypond/lily/lily-parser.cc:116
#47 0x000055b7a974361d in ly_parse_file(scm_unused_struct*) 
(name=0x7ffc05f67630) at 
/home/john/src/gitlab/lilypond/lily/lily-parser-scheme.cc:125
#48 0x00007f75f24f306d in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#49 0x00007f75f24f8d5d in scm_call_n () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
--Type <RET> for more, q to quit, c to continue without paging--c
#50 0x00007f75f2475d0c in scm_call_1 () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#51 0x000055b7a97577a8 in Scm_variable::operator()(scm_unused_struct*) (arg1=<optimised 
out>, this=<optimised out>) at 
/home/john/src/gitlab/lilypond/lily/include/lily-modules.hh:73
#52 main_with_guile(void*, int, char**) () at 
/home/john/src/gitlab/lilypond/lily/main.cc:576
#53 0x00007f75f248e981 in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#54 0x00007f75f246fdfe in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#55 0x00007f75f24f306d in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#56 0x00007f75f24f8d5d in scm_call_n () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#57 0x00007f75f24e6bcd in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#58 0x00007f75f24704c9 in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#59 0x00007f75f2470529 in scm_c_with_continuation_barrier () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#60 0x00007f75f24e59d2 in  () at /usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#61 0x00007f75f23dc53b in GC_call_with_stack_base () at 
/usr/lib/x86_64-linux-gnu/libgc.so.1
#62 0x00007f75f24e5adc in scm_with_guile () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#63 0x00007f75f248eae6 in scm_boot_guile () at 
/usr/lib/x86_64-linux-gnu/libguile-2.2.so.1
#64 0x000055b7a9623560 in main(int, char**) (argc=2, argv=0x7ffc05f68088) at 
/home/john/src/gitlab/lilypond/lily/main.cc:913