[U-Boot] [PATCH v1] env: fix crash using default -f -a

[Stefano Babic <sbabic@denx.de>]

On 05/10/2012 12:58, Gerlando Falauto wrote:

> My idea here was to "apply" the changes as soon as the environment gets
> changed, like it would happen with a manual "setenv"/"env set".
> So for instance, if you switch from a custom baudrate back to the
> default baudrate, you get a message prompting you to switch to the new
> baudrate (which actually *DOES* change on the console).

This is exactly the reason I am personally not so convinced to do it.
This forbids to reset the environment in a script. In fact, nobody wants
that a script stops waiting for input.

Think this use case. A board come back from field and in the factory the
original status should be restored. It can be easy done with a script
that contains "env default -f -a", plus parts to restore the original
software. The whole script should run, and not wait for input.

My personal opinion is that who issues such commands (as restoring the
environment, or destroying data in flash, or..) knows what is doing and
it should not be forbidden to do what he minds.

> 
> Whether that should also be performed as a "cleanup" action upon
> restoring defaults, well I am not sure...

I explained my opinion above ;-). But this has nothing to do with the
patch, that must fix a crash.

> 
>>> So by adding these extra checks you're subtly canceling those efforts.
>>
>> That is correct, but in any case a check for a NULL pointer should be
>> done before accessing to the pointer, independently what we want to do
>> with it.
> 
> Absolutely. See my proposed patch.
> 
>>> So I would rather provide a default value to prevent the crashes,
>>> instead of skipping settings altogether. Posting a patch in a few
>>> minutes.
>>
>> Ok, I will review it. In any case, we need a fix for the coming release.
> 
> Absolutely. Once again, I cannot apologize and thank you enough for
> reporting and digging into this.
> I assumed providing an own patch would make more sense than asking you
> to review yours, not sure whether it is popular practice to do so.

Never mind. It is only important to fix the bug ;-)

Best regards,
Stefano

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