In qio_channel_command_new_spawn() the 'flags' variable is checked
to see if /dev/null should be used for stdin or stdout; first with
O_RDONLY and then O_WRONLY.  However the second check for O_WRONLY
is only needed if flags != O_RDONLY and therefore should be an
else if statement.

This minor optimization has the added benefit of suppressing a warning
from a static analysis tool (Parfait) which incorrectly reported an
incorrect checking of flags in qio_channel_command_new_spawn() could
result in an uninitialized file descriptor being used. Removing this
noise will help us better find real issues.

Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com>
---
 io/channel-command.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/io/channel-command.c b/io/channel-command.c
index 3e7eb17eff54..82acd3234915 100644
--- a/io/channel-command.c
+++ b/io/channel-command.c
@@ -61,8 +61,7 @@ qio_channel_command_new_spawn(const char *const argv[],
 
     if (flags == O_RDONLY) {
         stdinnull = true;
-    }
-    if (flags == O_WRONLY) {
+    } else if (flags == O_WRONLY) {
         stdoutnull = true;
     }
 
-- 
1.8.3.1

On 08/31/2018 11:36 AM, Liam Merwick wrote:
> In qio_channel_command_new_spawn() the 'flags' variable is checked
> to see if /dev/null should be used for stdin or stdout; first with
> O_RDONLY and then O_WRONLY.  However the second check for O_WRONLY
> is only needed if flags != O_RDONLY and therefore should be an
> else if statement.
> 
> This minor optimization has the added benefit of suppressing a warning
> from a static analysis tool (Parfait) which incorrectly reported an
> incorrect checking of flags in qio_channel_command_new_spawn() could
> result in an uninitialized file descriptor being used. Removing this
> noise will help us better find real issues.
> 
> Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com>
> ---
>   io/channel-command.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

> 
> diff --git a/io/channel-command.c b/io/channel-command.c
> index 3e7eb17eff54..82acd3234915 100644
> --- a/io/channel-command.c
> +++ b/io/channel-command.c
> @@ -61,8 +61,7 @@ qio_channel_command_new_spawn(const char *const argv[],
>   
>       if (flags == O_RDONLY) {
>           stdinnull = true;
> -    }
> -    if (flags == O_WRONLY) {
> +    } else if (flags == O_WRONLY) {
>           stdoutnull = true;
>       }
>   
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org