bug#24903: "tail -f - foo" does not terminate when stdin is closed and foo is ignored

[Pádraig Brady]

On 08/11/16 16:39, Julian Büning wrote:
> We observed another behavior possibly related to bug #24495:

Similar yes.

> $ mkdir foo
> $ echo "bar" | tail -f - foo &
> [1] 16386
> ==> standard input <==
> bar
> 
> ==> foo <==
> tail: error reading 'foo': Is a directory
> tail: foo: cannot follow end of this type of file; giving up on this name
> $ jobs
> [1]+  Running                 echo "bar" | tail -f - foo &

Yes we should exit here.

> $ readlink /proc/16386/fd/0
> pipe:[162156]
> $ lsof | grep 162156
> tail      16386          user    0r     FIFO       0,10       0t0
> 162156 pipe
> 
> Only the reading end of the pipe is still open, thus tail should not be
> able to read any more bytes from it.

Right we're not blocked on read()

The attached should fix it up.

thanks,
Pádraig.

p.s. These Symbolic Execution techniques are intriguing.
Have you any more details.

tail-f-ignore.patch
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