[mkgmap-dev] Commit: r673: When a reader plugin already contains an empty top level zoom, then we do not want to create a new one

Version 673 was commited by steve on 2008-08-25 15:46:18 +0100 (Mon, 25 Aug 2008) When a reader plugin already contains an empty top level zoom, then we do not want to create a new one so mark such levels specially and use them for creating the empty level instead of creating our own. Thanks to Pazapas for pointing this out.