anomalous colours in size_t f()

[Duarte Fusco]

Hello

A fragment of C code like the following:

  int main(void) {
    f1(void);
  }
  
  int f2(void) {
  }

is usually displayed in emacs in  a way such that:
the types are displayed in green colour: int, void
the functions being defined are displayed in blue colour: main, f2
the functions being called are displayed in white colour: f1

Now, when I write this:

  int main(void) {
    f1(void);
  }

  size_tf2(void) {
  }

size_tf2 is displayed in blue colour, which is all right. Then I type a space 
between size_t and f2:

  int main(void) {
    f1(void);
  }

  size_t f2(void) {
  }

Now, I was expecting to get size_t in green colour and f2 in blue colour, but 
the fact is I always get size_t in blue colour and f2 in white colour.

Is this anomaly a bug in emacs?

Duarte