This fixes a problem where ogg123 takes 100% of the cpu and is
unable to be stopped with anything less than 'kill -9' when outputting
to a pipe which closes.

My test is:

  ./ogg123 -d wav -f - test.ogg | less

then press q to quit less. Ogg123 will hang and start taking 100% of
the CPU.

Index: ogg123/buffer.c
===================================================================
--- ogg123.orig/buffer.c	2008-05-01 19:21:12.000000000 -0700
+++ ogg123/buffer.c	2008-05-01 19:32:16.000000000 -0700
@@ -207,7 +207,7 @@
 
   /* This test is safe since curfill will never decrease and eos will
      never be unset. */
-  while ( !(buf->eos && buf->curfill == 0)) {
+  while ( !(buf->eos && buf->curfill == 0) && !buf->abort_write) {
 
     if (buf->cancel_flag || sig_request.cancel)
       break;
@@ -251,6 +251,11 @@
 		    write_amount == buf->curfill ? buf->eos : 0,
 		    buf->write_arg);
 
+    if (!write_amount) {
+      DEBUG("Error writing to the audio device. Aborting.");
+      buffer_abort_write(buf);
+    }
+
     LOCK_MUTEX(buf->mutex);
 
     buf->curfill -= write_amount;
@@ -746,7 +751,7 @@
   pthread_cleanup_push(buffer_mutex_unlock, buf);
 
   LOCK_MUTEX(buf->mutex);
-  while (!empty) {
+  while (!empty && !buf->abort_write) {
 
     if (buf->curfill > 0) {
       DEBUG1("Buffer curfill = %ld, going back to sleep.", buf->curfill);