[BZ#538841] Images not rendering with small patterns

Submitted by fib..@..com

Description

Please describe the problem: If a certain rsvg execution causes a pattern tile to have a (horizontal or vertical) size of less than one pixel in the rendered image, the whole image will fail to render.

Steps to reproduce: Consider, for example, the following SVG file:

I would expect the filling of the first square to be indistinguishable from a solid red filling - and this is in fact what I get when I render the image at a width of 100 pixels or more (rsvg -w 100 File.svg File.png). However, when rendering it at a width of less than a 100 pixels (note that this would require a pattern tile to have a width of less than one pixel), all I get is a fully transparent PNG file of the required size.

Actual results: I get a transparent PNG file.

Expected results: I would expect a PNG file containing a solid red square with a thick black border, underneath a solid green square.

Does this happen every time? Yes.

Other information: