cat (GNU textutils) 1.22
GNU bash, version 1.14.7(1) r3 w/multibyte extension

When cat gets input from stdin under bash, i.e.
bash$ cat -
and the input is then terminated with ^Z, subsequent identical invocations
cause cat to return immediately without accepting input.

For more details, search the djgpp mail archives using 'bash cat' and locate the 
thread 'bash$ cat -'.

This is a DOS misfeature: the EOF condition on the console device is not
cleared until something is written to the console.  Since Bash uses BIOS
rather than DOS for I/O, it doesn't clear the EOF condition when it prints
the prompt.