Segfault when width is unspecified in legend position

[adigitoleo]

Affects both modern mode and classic mode. The following snippet plots correctly if any width parameter is added inside position.

julia> legend(
           region = (0, 10, 0, 8),
           (;
               symbol1 = (;
                   dx_left = 0.25,
                   marker = "-",
                   size = 0.33,
                   pen = 2,
                   fill = :black,
                   dx_right = 0.75,
                   text = "1s delay time",
               ),
               symbol2 = (;
                   dx_left = 0.25,
                   marker = :star,
                   size = 0.5,
                   pen = :false,
                   fill = :yellow,
                   dx_right = 0.75,
                   text = "Epicentre",
               ),
           ),
           position = (; inside = :BL, anchor = :BL),
           box = (; pen = 0.5),
       )

signal (11): Segmentation fault
in expression starting at REPL[17]:1
GMT_pslegend at /usr/lib/libgmt.so (unknown line)
GMT_Call_Module at /usr/lib/libgmt.so (unknown line)
GMT_Call_Module at /home/admin/.julia/packages/GMT/jguOm/src/libgmt.jl:147 [inlined]
gmt at /home/admin/.julia/packages/GMT/jguOm/src/gmt_main.jl:292
finish_PS_module at /home/admin/.julia/packages/GMT/jguOm/src/common_options.jl:3533
finish_PS_module at /home/admin/.julia/packages/GMT/jguOm/src/common_options.jl:3473 [inlined]
#legend#397 at /home/admin/.julia/packages/GMT/jguOm/src/pslegend.jl:65
legend##kw at /home/admin/.julia/packages/GMT/jguOm/src/pslegend.jl:51 [inlined]
#legend#403 at /home/admin/.julia/packages/GMT/jguOm/src/pslegend.jl:219 [inlined]
legend##kw at /home/admin/.julia/packages/GMT/jguOm/src/pslegend.jl:219
unknown function (ip: 0x7efc0d528b56)
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2247 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2429
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1788 [inlined]
do_call at /buildworker/worker/package_linux64/build/src/interpreter.c:126
eval_value at /buildworker/worker/package_linux64/build/src/interpreter.c:215
eval_stmt_value at /buildworker/worker/package_linux64/build/src/interpreter.c:166 [inlined]
eval_body at /buildworker/worker/package_linux64/build/src/interpreter.c:587
jl_interpret_toplevel_thunk at /buildworker/worker/package_linux64/build/src/interpreter.c:731
jl_toplevel_eval_flex at /buildworker/worker/package_linux64/build/src/toplevel.c:885
jl_toplevel_eval_flex at /buildworker/worker/package_linux64/build/src/toplevel.c:830
jl_toplevel_eval_in at /buildworker/worker/package_linux64/build/src/toplevel.c:944
eval at ./boot.jl:373 [inlined]
eval_user_input at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:150
repl_backend_loop at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:244
start_repl_backend at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:229
#run_repl#47 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:362
run_repl at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:349
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2247 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2429
#930 at ./client.jl:394
jfptr_YY.930_40362.clone_1 at /usr/lib/julia/sys.so (unknown line)
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2247 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2429
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1788 [inlined]
jl_f__call_latest at /buildworker/worker/package_linux64/build/src/builtins.c:757
#invokelatest#2 at ./essentials.jl:716 [inlined]
invokelatest at ./essentials.jl:714 [inlined]
run_main_repl at ./client.jl:379
exec_options at ./client.jl:309
_start at ./client.jl:495
jfptr__start_40531.clone_1 at /usr/lib/julia/sys.so (unknown line)
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2247 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2429
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1788 [inlined]
true_main at /buildworker/worker/package_linux64/build/src/jlapi.c:559
jl_repl_entrypoint at /buildworker/worker/package_linux64/build/src/jlapi.c:701
main at julia (unknown line)
__libc_start_main at /usr/bin/../lib/libc.so.6 (unknown line)
unknown function (ip: 0x400808)
Allocations: 12158722 (Pool: 12153201; Big: 5521); GC: 14

^C
zsh: segmentation fault (core dumped)  julia --banner=no --project=$PWD

[joa-quim]

Yes, shared guilty. GMT should check it to avoid the crash (opened an issue) and GMT.jl should error when not provided.
The fact is, the width is a mandatory argument.

[joa-quim]

Dealt with in #829

[joa-quim]

FYI, I've reverted the need for a width in #832
In fact GMT can compute it ... if we don't feed it with a GMTdataset with an empty coordinates matrix. Part of it discussed in GenericMappingTools/gmt#6313