Text Editor word-skip navigation doesn't always stop at spaces

Qt Creator 2.52 Linux and 2.6 Mac...

If I have the following code:
LightPositionSamples samples;

and put the text caret after the space, then hold down Ctrl + Shift and press the left arrow key, I'd expect the selection to stop before the space, but it doesn't, it goes to the beginning of the line (this is with "Enable built-in camel case navigation" turned off in Text Editor -> Behaviour - with this on, it stops between "Position" and "Samples").