spurious horizontal fill lines on unfilled polygons at low zoom levels

[whitis]

When converting state outline data, I found that for various states that inkscape would perform an unauthorized partial fill of the outline at various zoom levels, especially low zoom levels. This was seen for all states combined and for individual state files.

Looks like a classic case of a rasterization/fill algorithm being confused counting edges by minute details but why is such an algorithm even running on unfilled region?

What happens if you actually try to fill is an exercise for the reader.

One such state outline is attached.

Converted using: http://www.carto.net/svg/utils/shp2svg/

Original data from: http://www.census.gov/geo/www/cob/st2000.html

wget http://www.census.gov/geo/cob/bdy/st/st00shp/st51_d00_shp.zip
 ./ogis2svg.pl --input st51_d00.shp --output virginia.svg --roundval 0.000001 --outputunits mm <<\...EOF...
y
y
y
y
y
y
y
y
y
y
y
none
y
name
y
a

n
...EOF...
inkscape virginia.svg &

To see the same error on multiple states, use the st99 file.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: inkscape 0.48.2-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
CheckboxSubmission: 1e1a99f31ec2933306456e1f141c45d8
CheckboxSystem: edda5d4f616ca792bf437989cb597002
Date: Wed Dec 14 23:34:48 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: inkscape
UpgradeStatus: Upgraded to oneiric on 2011-11-09 (35 days ago)

[su_v (suv-lp)]

Reproduced with Inkscape 0.48.2 on Mac OS X 10.5.8 (i386): the attached SVG file displays horizontal lines at various zoom levels.
Not reproduced with Inkscape 0.48+devel r19773 (with the new cairo-based renderer).

Proposing to link as duplicate to e.g.
Bug #168595 “Renderer: adds horizontal lines”
<https://bugs.launchpad.net/inkscape/+bug/168595>

[su_v (suv-lp)]

Correction:
- Not reproduced with Inkscape 0.48+devel r19773
+ Not reproduced with Inkscape 0.48+devel r10773 (current trunk)

[su_v (suv-lp)]

The new renderer (part of the next major release 0.49) no longer exposes these rendering errors.
<http://wiki.inkscape.org/wiki/index.php/Release_notes/0.49#Inkscape_0.49>

On linux, you can test current development builds from this PPA:
<https://launchpad.net/~inkscape.dev/+archive/trunk>

Linking as duplicate to bug #168595 - please add a comment here and revert the duplicate status if you don't agree and think these are different issues.