kernel32: Overhaul the handling of argv in set_process_name().

[Ken Thomases]

On Jul 13, 2016, at 2:37 PM, Sebastian Lackner <sebastian at fds-team.de> wrote:
> 
> On 13.07.2016 21:25, Sebastian Lackner wrote:
>> On 13.07.2016 20:20, Ken Thomases wrote:
>>>>> However, setproctitle() is specifically documented as a preferred
>>>>> alternative to the technique of overwriting the arg strings, so
>>>>> don't shift the strings if that's available.
>>>> 
>>>> Wouldn't it make sense to remove the directory component also in
>>>> this case, to be consistent? By moving the code to the bottom all
>>>> functions would be called in the same way.
>>> 
>>> Well, the only reason we remove the directory component for the other
>>> calls is because they only allow limited storage.  I'm not aware of a
>>> similar limit for setproctitle().
>>> 
>>> Also, setproctitle() is theoretically more similar to the shifting of
>>> the argument strings than to setprogname() or prctl(PR_SET_NAME).
>>> And we don't make any attempt to remove the directory component for
>>> the string shifting.  (I.e. "ps" will show the full command line,
>>> potentially including Windows-style .exe path.)
>> 
>> Well, its still very different compared to shifting because all the
>> following arguments are stripped away. I did some quick tests and it
>> seems like there are also methods which do preserve the additional
>> arguments in the "ps" output:
>> 
>> * Either a direct sysctl invocation as done in the setproctitle()
>>  implementation itself.
>> 
>> * Or, first shift the arguments (both methods work), and then call:
>>  setproctitle("some string");
>>  setproctitle(NULL);
>>  The second call restores the process title as seen by the app.
> 
> Actually it looks like we can get the same result just by concatenating
> all arguments on the Wine side. The separation of the arguments is lost
> in the "ps" output anyway. Depending on how you want to proceed I'll
> probably send a patch after you are done with the cleanup. ;)

I'm happy to have my current patch committed and you can submit a patch to pass the concatenation of the args to setproctitle() if you like. :)

-Ken