[libvirt] [PATCH] vsh: add a necessary assertion

[Marc Hartmayer]

On Thu, Jan 04, 2018 at 08:20 PM +0100, John Ferlan <jferlan at redhat.com> wrote:
> On 12/18/2017 07:33 AM, Marc Hartmayer wrote:
>> This fixes the compilation error (compiled with the compiler option
>> '-03').
>>
>> In file included from ../../tools/vsh.c:28:0:
>> ../../tools/vsh.c: In function 'vshCommandOptStringQuiet':
>> ../../tools/vsh.c:838:30: error: potential null pointer dereference [-Werror=null-dereference]
>>      assert(!needData || valid->type != VSH_OT_BOOL);
>>
>> Signed-off-by: Marc Hartmayer <mhartmay at linux.vnet.ibm.com>
>> Reviewed-by: Boris Fiuczynski <fiuczy at linux.vnet.ibm.com>
>> ---
>>  tools/vsh.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/vsh.c b/tools/vsh.c
>> index e878119b988f..677eb9db3e41 100644
>> --- a/tools/vsh.c
>> +++ b/tools/vsh.c
>> @@ -816,8 +816,8 @@ vshCommandFree(vshCmd *cmd)
>>   * to the option if found, 0 with *OPT set to NULL if the name is
>>   * valid and the option is not required, -1 with *OPT set to NULL if
>>   * the option is required but not present, and assert if NAME is not
>> - * valid (which indicates a programming error).  No error messages are
>> - * issued if a value is returned.
>> + * valid or the option was not found (which indicates a programming
>> + * error).  No error messages are issued if a value is returned.
>>   */
>>  static int
>>  vshCommandOpt(const vshCmd *cmd, const char *name, vshCmdOpt **opt,
>> @@ -835,6 +835,8 @@ vshCommandOpt(const vshCmd *cmd, const char *name, vshCmdOpt **opt,
>>              break;
>>          valid++;
>>      }
>> +    assert(valid);
>> +
>
> Could we combine the subsequent one to have :
>
> assert(valid && (!needData || valid->type != VSH_OT_BOOL));

I think so. Might make error tracking a little bit more difficult, but
that should be okay.

> ?
>
> John
>
>>      assert(!needData || valid->type != VSH_OT_BOOL);
>>      if (valid->flags & VSH_OFLAG_REQ)
>>          ret = -1;
>>
>
--
Beste Grüße / Kind regards
   Marc Hartmayer

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