new bug in fgetc_unlocked ?

Hello

In recent snapshots, reading of terminfo data in Mandriva installer is
broken, fread returns less bytes than it should while the file is not
finished.

While investigating this, I ended up in fgetc_unlocked

Commenting the 2 following lines fixes my bug but I don't understand
why :

if (__likely(stream->bm<stream->bs))
  return stream->buf[stream->bm++];

There is however something that look very strange then:

  if (__fflush4(stream,BUFINPUT)) return EOF;
  if (__unlikely(stream->bm>=stream->bs)) {

__fflush4 will ensure that  stream->bm == stream->bs == 0, so __unlikely
is strange, and actually I think that full test is useless.

Why not doing something like the following :

  if (__unlikely(stream->bm>=stream->bs)) {
    if (__unlikely(feof_unlocked(stream)))
      return EOF;
    if (__fflush4(stream,BUFINPUT)) return EOF;
    ssize_t len=__libc_read(stream->fd,stream->buf,stream->buflen);
    if (len==0) {
      stream->flags|=EOFINDICATOR;
      return EOF;
    } else if (len<0) {
kaputt:
      stream->flags|=ERRORINDICATOR;
      return EOF;
    }
    stream->bm=0;
    stream->bs=len;
  }
  c=stream->buf[stream->bm];
  ++stream->bm;
  return c;