dummyfs: returning -1 by write(), when reading 0 bytes from NULL buffer

[damianloew]

• According to POSIX it should return 0 instead of -1 in the following case:

  int main(void)
  {
      int fd;
  
      fd = open("testfile", O_RDWR | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
      printf("ret = %d\n", write(fd, NULL, 0));
  
      return 0;
  }

  

  

  https://pubs.opengroup.org/onlinepubs//9699919799.2018edition/ -> pwrite, write - write on a file

• Line of code that causes issue: https://github.com/phoenix-rtos/phoenix-rtos-filesystems/blob/b699b05c6d8d7f97944771cdb57bb1659cd87696/dummyfs/dummyfs.c#L755-L756

[damianloew]

Needed for running all libc unit tests on dummyfs targets