Bug 50598

Summary:	images with EXTEND_PAD may get rendered at the wrong position
Product:	cairo	Reporter:	Benjamin Berg <benjamin>
Component:	pdf backend	Assignee:	Adrian Johnson <ajohnson>
Status:	RESOLVED FIXED	QA Contact:	cairo-bugs mailing list <cairo-bugs>
Severity:	normal
Priority:	medium
Version:	1.12.2
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:
Attachments:	Patch that fixes the issue, no idea how correct it is ...

Description Benjamin Berg 2012-06-01 13:03:48 UTC

Created attachment 62394 [details]
Patch that fixes the issue, no idea how correct it is ...

When an image rendered using EXTEND_PAD and clipped at the same time it may be rendered at the wrong position.
The specific usecase that happened for me was rendering part of a PDF (scanned document) into a new PDF surface using popplers render() function (not render_for_printing because of bug #44002.

I'll attach a patch that fixes the issue for me. It seems that the offset is set on the created image surface in _cairo_pdf_surface_add_padded_image_surface, however it is then not used inside _cairo_pdf_surface_add_source_surface.

Comment 1 Adrian Johnson 2012-06-02 02:35:44 UTC

I've fixed the bug with a different patch. The problem with using cairo_surface_get_device_offset internally is that images passed to the pdf backend have already had the device offset applied to the pattern matrix. And we don't want to apply the offset twice.

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