fix compilation with -Werror=unused-result

[mzanetti]

After upgrading to ubuntu artful (17.10) the new gcc seems to have -Werror=unused-result on by default which breaks compilation.

from man 2 getcwd:

On failure, these functions return NULL, and errno is set to indicate the error. The contents of the array pointed to by buf are undefined on error.

Now, the interesting bit is that if I compare the result with NULL, it actually fails with NULL used in arithmetic [-Werror=pointer-arith] so checking for 0... Not sure if this is pretty enough, but at least gets around the issue and shouldn't do any wrong.

[vareddy-zz]

Hi @mzanetti,
Thank you for providing this pull request! We currently haven't tested the SDK in Ubuntu 17.10 hence we weren't able to catch this compile failure.
This pull request has no conflicts so we will include this in a future release.
Please let us know if you have any more questions or suggestions.
Thanks!
Varun

[vareddy-zz]

Hi @mzanetti,
I believe the error with using NULL is due to a typo in your pull request.
The brackets are closed incorrectly, hence the compiler thinks that you are checking the size of the buffer with NULL i.e. :
if (getcwd(CurrentWD, sizeof(CurrentWD) == 0))
should actually be
if (getcwd(CurrentWD, sizeof(CurrentWD)) == NULL)
The above line compiles correctly and throws no errors.
Thanks!
Varun

[mzanetti]

facepalm

Thanks for spotting that :) Updated.

[vareddy-zz]

Included in v1.2.0.