The intent of the SWT.MOZILLA style
is actually to indicate that XULRunner must be used, and therefore JavaXPCOM
may be used. On Windows and OSX this distinction comes for free because
XULRunner is the only way to use a Mozilla-based Browser, but on Linux
the style's name is a bit confusing (if it was SWT.XULRUNNER then this
case would be more obvious). Specifying/omitting this style does
make functional differences on Linux in order to remain consistent with
the other platforms:
-> creating a Browser with SWT.MOZILLA
will fail if it doesn't find a XULRunner (even if it could find an embeddable
Firefox or Mozilla, because these do not offer JavaXPCOM support)
-> Browser.getWebBrowser() will answer
null for SWT.NONE-style Browsers, even if XULRunner happens to be the renderer
being used
So back to your original question, it
is behaving as intended. The style is meant to indicate the intent
of the Browser creator, not to determine later which native renderer is
being used. A Browser created with style SWT.NONE should have the
same capabilities on all platforms, as should a Browser created with style
SWT.MOZILLA.