PVS-Studio warning V527 for Scilab

void GetenvB(char *name, char *env, int len)
{
  int ierr = 0, one = 1;
  C2F(getenvc)(&ierr,name,env,&len,&one);
  if (ierr == 0)
  {
    char *last = &env[len-1];
    while ( *last == ' ' ) { last = '\0' ; }
    last--;
  }
  ....
}

Most likely this is what should be written here: while ( *last == ' ' ) { *last++ = '\0' ; }

This suspicious code was found in Scilab project by PVS-Studio static code analyzer.
Warning message is:
V527 It is odd that the '\0' value is assigned to 'char' type pointer. Probably meant: *last = '\0'. getenvb.c 24

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/