Description:
When using 'read -u 3' or the like, and the pipe-buf already contains
more than one line, the first line is returned, and bytes up to the next
multiple of 128 are skipped.

http://lists.gnu.org/archive/html/bug-bash/2005-03/msg00168.html
http://lists.gnu.org/archive/html/bug-bash/2005-03/msg00173.html
http://bugs.gentoo.org/show_bug.cgi?id=87093

--- a/builtins/read.def
+++ b/builtins/read.def
@@ -276,7 +276,7 @@
   input_is_tty = isatty (fd);
   if (input_is_tty == 0)
 #ifndef __CYGWIN__
-    input_is_pipe = (lseek (0, 0L, SEEK_CUR) < 0) && (errno == ESPIPE);
+    input_is_pipe = (lseek (fd, 0L, SEEK_CUR) < 0) && (errno == ESPIPE);
 #else
     input_is_pipe = 1;
 #endif