bugfix/get-config problem with TEXT type

[babisboloudakis]

fixes #7

Fix a problem where, when trying to call the /get-config
service on a text field, you would first get wrong data,
and on the second call the node would crash.

[Karsten1987]

I hope you don't mind me editing your post. I've linked it to the issue you opened because I think they are related. Let me know if that's incorrect.

Also, can you somehow tell me how to test this PR?

[babisboloudakis]

Indeed, this PR attempts to solve the issue, thanks for linking.

In order to test it, I suggest that you start a photo_node with a camera connected. Then try to call the /photo/get_config service on a TEXT configuration ( like artist, cameramodel, ownername etc. )
For example:
$ rosservice call /photo/get_config "param: 'artist'"
This should return something like:
value: "<camera's configuration>"

If you try the same on the previous version you should get 'junk' data on the first service call, and a segmentation fault on the second call.

[Karsten1987]

thanks for the patch!