[poppler] PDF compliance, regarding Annot /Rect

[Tobias Deiminger]

Leonard, there was a very interesting conversation between you and Fabio, see https://lists.freedesktop.org/archives/poppler/2012-April/008948.html.

Fabio wonders why acroread does not clip Annot Line [0 0 200 200] to Anot Rect [0 0 100 100]. You said:
> Acrobat & Adobe Reader must certainly clip an annotations appearance to the bounding area of the annotation.

but also added
> HOWEVER, it doesn't have a prebuilt appearance [...] Since your line has an L (the actual line coords) of [0 0 200 200], that causes Acrobat/Reader to generate a new bounding box that incorporates the entire line as that is what one would expect.

Last week you answered my question about Annot Rect:
> However, you are completely correct that drawing an AP (either
> pre-generated or dynamically created) outside of the Rect is a bug.

With my limited knowledge the answers seem a bit incompatible to me.
Fabios Annot Line [0 0 200 200] needs to be dynamically generated.
Following "drawing an AP (pre-generated or dynamically created) outside of the Rect is a bug"
=> This means if we don't clip the Line, it's a bug.
Following "incorporates the entire line as that is what one would expect"
=> This means if we don't clip the Line, it's NOT a bug, but expected.

Could you clarify this?

One more, if you have some time left: What about the algorithm from ISO 32000-1:2008, 12.5.5 - It says we have to *scale* appearances into Annot Rect, not only clipping them. Does this apply to the Annot Line example? If I consider it as dynamically generated appearance and apply the algorithm, it would always be scaled (shrinked) into [0 0 100 100]. No chance to get the Adobe behavior this way, is it?

Thanks a lot,
Tobias