This causes an issue for the 'Gnu' coding style because it defaults to a spacing of 4 as of astyle 2.02.
I don't know the coding style, but either it's a bug in astyle (in that case please blame the astyle team) or the style really has changed to be like that. What's the cause?
I believe the astyle team made the decision (right or wrong) to rely on the user to set the indent level. As per the 'astyle --help' output:
--indent=tab OR --indent=tab=# OR -t OR -t#
Indent using tab characters, assuming that each
tab is # spaces long. Not specifying # will result
in a default assumption of 4 spaces per tab.
The Gnu coding style (as implemented in astyle < 2.02) is to use an indent spacing of 2, not 4. I haven't followed up with the astyle team to determine if this is design intent or a bug, but will do so. In the meantime, if you could have the 'Indentation size (in spaces):' be available irregardless of coding style it would be greatly appreciated.