KMimeMagic and text/x-c++

[Alexander Dymo]

I've discovered that mime magic fails to return the correct mime 
type for c++ files

For example,
KMimeType::mimeType() returns KMimeType::Ptr initialized with 0 pointer
because previous calls to KMimeMagic::findBufferType return 
"text/x-c++" as a part of KMimeMagicResult.

And KMimeTypeFactory::findMimeTypeByName() does not find the right
KMimeType because we have only "text/x-c++hdr" and "text/x-c++src".

What would be the right way to fix this? Introduce text/x-c++ mimetype
or fix the magic?