GNU Indent 2.2.9 unary minus erroneous whitespace removal

GNU Indent 2.2.9 erroneously removes / fails to reinsert whitespace 
between a pair of unary minus operators; thus changing double negation 
"- -x" into a self decrement "--x"; for example changing the legal code 
below into illegal code:

$ cat example.c
 
int main(void)
{
  return - -0;
}
 
$ indent --verbose example.c
There were 5 non-blank output lines and 0 comments
$ cat example.c
 
int
main (void)
{
  return --0;
}


or worst still, performing silent until runtime corruption of a variable.

rgds
Simon.