No luck: i tested with the very latest cairo-1.5.4, issue is still there.
You can check the attached PDF, created starting from the abovementioned SVG source.
It seems to an inkscape issue: i tested an SVG => PDF conversion using Carl Worth's svg2pdf utility, and it created the PDF with correct outline (not broken).
If i'm not wrong, that utility uses cairo and librsvg, so i definitively think cairo is "not guilty".
No luck: i tested with the very latest cairo-1.5.4, issue is still there.
You can check the attached PDF, created starting from the abovementioned SVG source.
It seems to an inkscape issue: i tested an SVG => PDF conversion using Carl Worth's svg2pdf utility, and it created the PDF with correct outline (not broken).
If i'm not wrong, that utility uses cairo and librsvg, so i definitively think cairo is "not guilty".
Is there some other test you want me to try?