Hello Ivan,
I think I found where my extended-type lines disappear. They are simply not taken into account when estimating subdivision size, i.e:
MapArea.java, lines 389-394
private void addSize(MapElement p, int[] sizes, int kind) {
-> if(p.hasExtendedType()) { -> // not applicable for elements with extended types -> return; -> }
So subdivisions end up too big (and are not drawn correctly) if there are a lot of extended-type elements. I commented out above lines in MapArea.java, rebuilt mkgmap (r1274) and seems to work, i.e. extended lines are no longer dropped in i.e. MapSource.
I am not sure if I am breaking anything else, so please, somebody who understands the code and implications more, please check this.
Extended type elements are not stored in the subdivision in the same manner as the non-extended elements so it is not appropriate to take their sizes into account in the same way as the elements with non-extended types. However, there could well be some limit to the amount of extended type elements that a subdivision has. The offsets and sizes are 32 bit but that doesn't mean to say you can have huge amounts of those elements in a single subdivision. I could introduce some threshold that would cause a subdivision to be split if the extended type elements are larger than that. Cheers, Mark