Description of problem:

I have crash report in msort (1993620), this started in Fedora 34, while
Fedora 33 and older works fine.

The crash is related to ICU, I get:

(gdb) bt
#0  0x00007ffff7bfa2a2 in raise () from /lib64/libc.so.6
#1  0x00007ffff7be38a4 in abort () from /lib64/libc.so.6
#2  0x00007ffff5d37a46 in __gnu_cxx::__verbose_terminate_handler() [clone .cold] ()
   from /lib64/libstdc++.so.6
#3  0x00007ffff5d4329c in __cxxabiv1::__terminate(void (*)()) () from /lib64/libstdc++.so.6
#4  0x00007ffff5d43307 in std::terminate() () from /lib64/libstdc++.so.6
#5  0x00007ffff5d435a9 in __cxa_throw () from /lib64/libstdc++.so.6
#6  0x00007ffff5d3a830 in std::__throw_system_error(int) () from /lib64/libstdc++.so.6
#7  0x00007ffff7df4fff in icu_67::umtx_initImplPreInit(icu_67::UInitOnce&) ()
   from /lib64/libicuuc.so.67
#8  0x00007ffff7e71b77 in icu_67::Norm2AllModes::getNFCInstance(UErrorCode&) ()
   from /lib64/libicuuc.so.67
#9  0x00007ffff7e71bbd in icu_67::Normalizer2::getNFCInstance(UErrorCode&) ()
   from /lib64/libicuuc.so.67
#10 0x00007ffff7e7c10f in unorm_normalize_67 () from /lib64/libicuuc.so.67
#11 0x000055555556542d in NormalizeString (s=s@entry=0x5555555946e0,
    ResultLength=ResultLength@entry=0x7fffffffd5b8, type=UNORM_NFC)
    at /export/BUILD/msort-8.53/misc.c:687
#12 0x000055555555ef7d in main (ac=10, av=0x7fffffffda98)
    at /export/BUILD/msort-8.53/msort.c:1037


Line 687 in msort-8.53/misc.c is:

  *ResultLength = unorm_normalize(s16,-1,type, 0, NULL, 0, &status);

and moves on like this:

 Result = (UChar*) malloc(sizeof(UChar) * ((*ResultLength) + 1));
  if (!Result) {
    *ResultLength = 0;
    return NULL;
  }
  status = U_ZERO_ERROR;
  /* Add 1 to *ResultLength to allow addition of terminal null and prevent error code */
  CharsNormalized = unorm_normalize(s16, -1,type, 0, Result, (*ResultLength+1), &status);
  free((void *) s16);
  if(status != U_ZERO_ERROR) {
    *ResultLength = -1;
    return NULL;
  }

So it seems like code does a trick to get length of result, this seems to have worked before, but
in Fedora it causes crash as shown above. However, I see ICU version in Fedora 33 and 34 are more or less identical. Do you know any change in ICU which can cause this?

Should the code be rrewritten in some way?

Thanks for any help.