These queries appear to be broken:
glGetProgramInterfaceiv(PrgName, GL_TRANSFORM_FEEDBACK_BUFFER, GL_MAX_NUM_ACTIVE_VARIABLES, &nVar);
glGetProgramInterfaceiv(PrgName, GL_TRANSFORM_FEEDBACK_BUFFER, GL_ACTIVE_RESOURCES, &nBuffers);
They both generate an invalid enum error.
Also, this would-be follow up query fails with invalid enum:
GLenum Prop = GL_BUFFER_BINDING;
glGetProgramResourceiv(PrgName, GL_TRANSFORM_FEEDBACK_BUFFER, iBuffer, 1, &Prop, 1, NULL, &iBinding);
The transform feedback seems to work properly though. (using the new xfb_buffer, xfb_stride, and xfb_offset layout qualifiers)
This is tested on this render context:
GLRenderer = AMD Radeon HD 7900 Series
GLVersion = 4.4.12874 Core Profile Forward-Compatible/Debug Context 184.108.40.206
GLShadingLanguageVersion = 4.30 (<-- also a bug?, I'm running programs compiled with #version 440)
Thanks for the report. We'll look into it.
As for the GLSL version report - yes, that's just a reporting bug. GLSL 440 is fully supported and shaders using #version 440 should work. We'll get a fix into an upcoming driver.