In my PHPStorm 8.0.1 "Soft wrap in editor" work somewhat diffrent that I expect.
If in my editor there line with length near "Right margin columns" value :
If I add several space before last parameter in function I got next:
But I expected that line would be "wrapped softly", I mean that there woul be not new line created,
but wrapped code started from left and at left margin of editor there would be mark that this line was "softly wrapped".