[musl] busybox problem on powerpc PPC/32bit (hardware TP-Link-WDR-4900-v1)

[Bastian Bittorf <bb@npl.de>]

With OpenWRT i recognized a strange behavior of ash-shell scripts.
It happens only on target PowerPC, e.g. m68k, arm, mips, x86 are
unaffected.

The visible strange behavior in 'ash' is:

$ test A -gt 5 && echo OK
ash: A: out of range
OK

Ofcourse this wrong returncode leads to all sorts of things...

I tested several busybox releases (1.33.2, 1.35.0, 1.36.0) and
crosscompiled with musl-git-b76f37f (from musl.cc) and 
crosscompiled with glibc: powerpc-linux-gnu-gcc (Debian-12.2.0)
(it's the same for all versions)

The resulting linux + busybox images ready for QEMU are here:
http://intercity-vpn.de/mpc85xx/

If needed i can provide build instructions.
Maybe somebody with more powerpc assembly knowledge can help here.

The underlying code is here:  
https://git.busybox.net/busybox/tree/coreutils/test.c#n488
But i can not spot the error:

static number_t getn(const char *s)
{
  char *p;
  errno = 0;
  r = strtol(s, &p, 10);
  if (errno != 0)
    syntax(s, "out of range");
  return r;
}

Best Greetings,
Bastian Bittorf