[libvirt] [PATCH 08/18] vshCommandOpt: Allow caller avoiding assert()

[Martin Kletzander]

On Thu, Jan 11, 2018 at 06:02:58AM -0500, John Ferlan wrote:
>
>
>On 01/11/2018 05:50 AM, Martin Kletzander wrote:
>> On Tue, Jan 02, 2018 at 06:12:01PM +0100, Michal Privoznik wrote:
>>> In the future, completer callbacks will receive partially parsed
>>> command (and thus possibly incomplete). However, we still want
>>> them to use command options fetching APIs we already have (e.g.
>>> vshCommandOpt*()) and at the same time don't report any errors
>>> (nor call any asserts).
>>>
>>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>>> ---
>>> tools/vsh.c | 7 ++++---
>>> tools/vsh.h | 3 ++-
>>> 2 files changed, 6 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/tools/vsh.c b/tools/vsh.c
>>> index ebc8d9cb1..d27acb95b 100644
>>> --- a/tools/vsh.c
>>> +++ b/tools/vsh.c
>>> @@ -815,8 +815,8 @@ 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 (which indicates a programming error) unless cmd->skipChecks
>>> + * is set. No error messages are issued if a value is returned.
>>>  */
>>> static int
>>> vshCommandOpt(const vshCmd *cmd, const char *name, vshCmdOpt **opt,
>>> @@ -829,7 +829,8 @@ vshCommandOpt(const vshCmd *cmd, const char *name,
>>> vshCmdOpt **opt,
>>>     /* See if option is valid and/or required.  */
>>>     *opt = NULL;
>>>     while (valid) {
>>> -        assert(valid->name);
>>> +        if (!cmd->skipChecks)
>>> +            assert(valid->name);
>>
>> This can segfault when cmd->skipChecks == False && valid->name == NULL,
>> which is what the assert() guarded before.
>>
>> So either STREQ_NULLABLE or another if.
>>
>
>Hmmm... Also see:
>
>https://www.redhat.com/archives/libvir-list/2017-December/msg00605.html
>
>it's related somewhat...
>

I don't see how, this is all wrapped in `while (valid)`
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