Way label not rendered on reversed way

[stephankn]

If the way is facing east to west the label is not rendered right. Reversing the way to point from west to east makes the rendering right.

Herm noted that placement tries to reverse the string in case it would render upside down. This might cause problems with unicode strings.

Look at http://c.tile.osm-tools.org/osm_th/18/203121/117166.png to see the correct rendering for สีวลี 06
The others point to the opposite direction and have rendering issues in 0.7. Mapnik2 does not render them at all.
http://c.tile.openstreetmap.org/18/203121/117166.png

with "unifont Medium" the label can be rendered.

This small OSM file contains a way with the label rendered right:
http://www.openstreetmap.org/api/0.6/way/149927352

reversing the way will trigger the problem

[herm]

After we switch to HarfBuzz mapnik will no longer process individual unicode characters in its placement finder but it will use glyphs. So the processing direction should no longer affect the rendering. However it has to be investigated why the label sometimes completely disappears.

[herm]

Closing this ticket as the issue is solved in the harfbuzz branch. Refs #1428.

[stephankn]

Harfbuzz fixed this issue:

Harfbuff

Mapnik