oops, did not actually flush the buffer

buffer/buffer_putflush.c

@@ -43,6 +43,7 @@ int buffer_putflush(buffer* b,const char* x,size_t len) {
 	return buffer_stubborn(b->op,b->fd,v[1].iov_base+w,v[1].iov_len-w,b);
       }
     }
+    b->p=0;
     return 0;
   }
 #endif