std::string and char* are sent differently (c-strings include the null terminator)

[j4m3s]

I'm not sure if this is a bug or not, but it wasn't what I expected.

When I send a char*, the value ends with the null terminator (\u0000). When I send a std::string, it does not. I would expect both to send the same characters.

For example:

NimBLECharacteristic::setValue("hello");
NimBLECharacteristic::notify();

sends 68-65-6C-6C-6F-00

whereas

NimBLECharacteristic::setValue(std::string("hello"));
NimBLECharacteristic::notify();

sends 68-65-6C-6C-6F (note the lack of -00!).

I noticed because I have been using my own "terminator", \n in order for the client to know if the string is very and hasn't been fully received. This worked fine until I used a c-string in one notification, and ended up with a \u0000 AFTER my \n terminator. Which was rather tricky for me to track down because, of course, the null terminator doesn't print out in the logs on the client so didn't show up :)

I'm happy for you to close the issue as invalid if this is working as intended, but thought I'd record it here for others.

[h2zero]

Thanks! These 2 methods should have the same result, so certainly this is not intended. I think an adjustment to remove the trailing NULL would be best, let me know your thoughts.

[j4m3s]

I agree, I'd remove the null. The end of a string at the client end will be handled by the programming language at the client end without us needing to send it :)

This could be a breaking change I guess, if anyone is only ever sending char* values and is relying on that null character being there. Might be worth mentioning in the change log?

[h2zero]

Yes it certainly should be noted as a possible breaking change. Thanks!