On 01/11/2017 12:24 PM, Nir Soffer wrote:
> From: Nir Soffer <nsoffer@redhat.com>
> 
> The result of openfile was not checked, leading to failure deep in the
> actual command with confusing error message, and exiting with exit code 0.
> 
> Here is one example - trying to read a pattern from an invalid chain:
> 
>     $ qemu-io -c 'read -P 1 0 1024' top.qcow2; echo $?

As written, you have to guess some context about how top.qcow2 was
created.  The example can be made a bit more reproducible with:

$ : > file
$ qemu-io -f qcow2 -c ... file

>     can't open device top.qcow2: Could not open backing file: Image is not in qcow2 format
>     no file open, try 'help open'
>     0
> 
> With this patch, we fail earlier with exit code 1:
> 
>     $ ./qemu-io -c 'read -P 1 0 1024' top.qcow2; echo $?
>     can't open device top.qcow2: Could not open backing file: Image is not
>     in qcow2 format
>     1
> 
> Signed-off-by: Nir Soffer <nirsof@gmail.com>
> ---
>  qemu-io.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)

Whether or not the commit message is improved,
Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org