#2493 Crash with -c flag and command line arguments

[Gabriel Dupras]

Gnuplot crashes when it is invoked with a command such as gnuplot -c script.gpi 1 2. This happens with gnuplot 5.4.3 on Windows 10, in cmd.exe.

Steps to reproduce the bug:
Create this file, named script.gpi:

print('start')
print(ARG0)
print(ARG1)
print(ARG2)
print('end')

Do gnuplot -c script.gpi. The expected output is

start
script.gpi


end

but instead gnuplot crashes and does not output anything.
Do gnuplot -c script.gpi 1. The output matches the expected output:

start
script.gpi
1

end

No issue here.
Do gnuplot -c script.gpi 1 2. The expected output is

start
script.gpi
1
2
end

but instead gnuplot crashes and does not output anything.

[Ethan Merritt]

I'm not seeing a crash under linux, but valgrind shows a read from uninitialized memory that may explain it. The attached patch prevents that, and hopefully it also fixes your crash.

[Tatsuro MATSUOKA]

In the current development source in which the above patch applied,

gnuplot -c script.gpi

still crashes.
I tried make with debug symbol and tried execute through gdb.
I made break point in misc,c however program seems to seg faults very early stage.

(gdb) r -c /d/Work/Tatsuro/cygwinwork/gnuplot/bug_etcs/2493/script.gp
Starting program: D:\Work\Tatsuro\msys2-gnuplot\gnuplot\gnuplot-main\gnuplot-main\config\mingw\gnuplot.exe -c /d/Work/Tatsuro/cygwinwork/gnuplot/bug_etcs/2493/script.gp
[New Thread 7504.0x1e60]
[New Thread 7504.0x19c8]
[New Thread 7504.0xcb0]

Thread 1 received signal SIGSEGV, Segmentation fault.
0x00007ffb4ce3a3ee in msvcrt!_strdup () from C:\WINDOWS\System32\msvcrt.dll

[Bastian Märkisch]

The index for the call arguments gets one too large which is causing the segfault. Fixed in master.

[Tatsuro MATSUOKA]

I have confirmed the fix in the master branch. Commit [d78e63]