No return statement in writePort()

[mmurdoch]

On compiling Firmata (e.g. when used within a sketch in the Arduino IDE) the following warning is generated:

...\Firmata/Boards.h: In function 'unsigned char writePort(byte, byte, byte)':
...\Firmata/Boards.h:371: warning: no return statement in function returning non-void

This will likely lead to unexpected behavior if writePort() is called and the return value manipulated.

[soundanalogous]

I didn't write this so I'm not sure what the author's intention was. I suspect that it should be changed to void since writePort does not return anything.

[mmurdoch]

Is writePort considered to be part of the public API? I suspect it may be as it's defined in Boards.h (which is included in a sketch by the Arduino IDE if the Firmata library is selected from the menu) and it is used in StandardFirmata. If so, changing the signature would break backward compatibility - existing sketches assigning the return value to a variable will no longer compile.

What's the policy around backwardly incompatible changes - does this require a major version number change (as in Semantic Versioning - http://semver.org/)?

[soundanalogous]

Yes Firmata uses semver. However, I think it could be an exception here since if anyone was trying to use the return value from writePort their could would not have compiled (of if it compiled it would not work as expected) so changing it to void would not actually break anyones existing code unless I'm overlooking something.

[soundanalogous]

Could also just return 1 as is done in Arduino write method.

[soundanalogous]

updated in dev branch to return 1