String::std_string() returns null terminator as part of string.

[jimfoltz]

https://github.com/TommyKaneko/Sketchup-API-C-Wrapper/blob/3f06f164448163b92bb12161bb694115899d056d/src/SUAPI-CppWrapper/String.cpp#L155

a char* char_array needs to be null terminated. A vector<char> does not. No need to add 1 here.

[jimfoltz]

Although maybe it's more correct to "chomp" the returned vector.

[TommyKaneko]

No, as long as it works without the extra character, we can get rid of it. Please test and make a pull request.

[thomthom]

That vector or char is fed to SUStringGetUTF8 which expects char*. Further more the documentation describe:

This function does not allocate memory. You must provide an array of sufficient length to get the entire string. The output string will be NULL terminated.

The +1 to the vector size is to ensure enough memory is allocated.

std::string is then receiving a NULL terminated char* - which is standard way to represent a string in C. It knows to stop at NULL. No need to "chomp".

Unless anyone is seeing incorrect string lengths returned? (That would be a good case for setting up in a test unit.)

[jimfoltz]

I am seeing an extra char - that's why I brought it up.

[jimfoltz]

It may bot be the null terminator, but I do get some extra thing at the end of a string. This image is from windows command line using less.exe pager. So some maybe binary thing there - no time now to investigate.

[thomthom]

hmm...

That would be junk uninitialised data. Might be the creation of the vector;

std::vector<char> char_array(out_length);

Does it change if it's all initialized to null?

std::vector<char> char_array(out_length, 0);

Let me use that as a sample for the unit tests I'm scaffolding.

[jimfoltz]

BTW the GetString() function you postyed has the same issue.

[thomthom]

I'm seeing that the std::string's size is one larger and contain a NULL byte:

I'll investigate closer.

[thomthom]

Ah, it was this line:

https://github.com/TommyKaneko/Sketchup-API-C-Wrapper/blob/3f06f164448163b92bb12161bb694115899d056d/src/SUAPI-CppWrapper/String.cpp#L159

That copies all the bytes, including NULL bytes.

Replacing it with std::string str(char_array.data()); made it scan and stop at the NULL terminator.

However, that prevents String from representing binary data.

Maybe it's better to keep using begin() and end() but omit trying to read the extra NULL termination.

[thomthom]

On second though, SUStringSetUTF8 relies on NULL termination, so there is no way it can represent binary data.

I'll switch to .data() and include it in my test unit PR.

[thomthom]

Btw Jim, those weird characters were probably a result of Release mode uninitialized char in the vector. In Debug it looks to init to 0 - but Debug allocate memory differently.