[OSM-talk] Mapnik: strange prioritisation/appearance of place names

[Woll Newall]

It looks as if this is veering (shooting!) off into a related but  
different topic - interesting but not really answering my question,  
which is basically: "Is there a 'city label' bug in the Mapnik slippy  
map on the OSM site?"!

Frederick suggests that the Fukuoka city label may not have been  
rendered at level 10 because of a clash with the airport symbol, but  
that wouldn't explain why the city label never appears in any level  
above 10 (when there shouldn't be anything else overlapping).

The same problem is more clearly shown if you zoom into the Maebaru  
city node (because the only things mapped there are the railway line  
and the city node). If I zoom really close in on the Maebaru city  
node, the label disappears, even though there's nothing else near it.

Zoom 13: The Maebaru city node is rendered, the Maebaru railway  
station is not (that is what you would expect).
http://tools.geofabrik.de/mc/?mt0=mapnik&mt1=googlemap&lon=130.20308&lat=33.55773&zoom=13

Zoom 15: The city node disappears, the station node appears. It really  
doesn't look as if the city node label would overlap with the station  
node label (if it had been drawn) there looks to be loads of space  
between them. There would only be an overlap with the station label if  
the text for the city label was about 8cm high on the screen!)
http://tools.geofabrik.de/mc/?mt0=mapnik&mt1=googlemap&lon=130.20308&lat=33.55773&zoom=15

Looking at it again directly on the OSM site slippy map, I see the  
same thing happening, plus the map, encompassing the Maebaru city and  
station nodes, is completely blank in level 17 and 18 - that can't be  
correct can it?! But I suspect that the blank map is a different  
problem to the city label one.

One logical explanation for the labels disappearing could be if the  
OSM Mapnik is a) Using a different database to render the city labels  
at lower zoom numbers, and b) failing to render the city labels at all  
from the OSM database at the higher zoom levels. Is that what the OSM  
Mapnik configuration does?

It's unclear to me to me how to get this question direct to the people  
who configure the OSM Mapnik slippy map layer - Should I just enter it  
as a bug into the bug report area on the mapnik.org site? I took a  
look at the existing bugs thre and they seem to be about "Mapnik", not  
"the Mapnik-created slippy map on the OSM site".Does anyone know how  
to report such things?

Cheers,
Woll