[mkgmap-dev] Really Serious bug when not using --route

Sun May 23 17:24:43 BST 2010

There is a serious bug that breaks routable maps when --route is NOT 
given. This bug will in future break routing on most GPS devices and is 
already inflicting Mapsource 6.16.1 and Basecamp 3.
This means that also if you compile maps that are not routable, you have 
to pass the --route parameter. Else the GPS / Mapsource looks into an 
empty NOD table and may crash. This will happen as soon as you mix 
routable maps with the non routable mkgmap created maps.

The problem is that Mapsource and the GPS search for 63440000.NOD data 
(63440000 as an example placeholder for the mapname). "Falagar", a 
developer at Garmin said to release a fix for this bug in Mapsource 
6.16.2 however mentioned that this fix will not be carried on to GPS 
devices and will still mean a deterioration of overall routing.

I'm not sure what the exact problem for this is (I just tried even very 
old mkgmap versions like 858 and also there the problem arises) but 
currently this means that --route should be the compulsory for all map 
creation, also not routable ones. If you have old maps (eg transparent 
contourline maps) that are troublesome to rebuilt, then opening with 
gpsmapedit, saving as mp and recompiling passing --route parameter is 
enough to solve the problem.

I think that until the bug is found, mkgmap should adopt --route as 
standard, because it may happen that if users put an mkgmap created 
without --route onto their GPS besides other routable maps, these maps 
might impact autorouting for the other routable maps (except if 
"deactivated" on the GPS).