[mkgmap-dev] Commit: r2679: With output-dir does not exist can result in error.

Version 2679 was committed by steve on Thu, 29 Aug 2013 With output-dir does not exist can result in error. If more than one thread then there is a race between testing the existence of the directory and creating it. Creating it results in an error if it already exists and the original code would fallback to the default directory on seeing this error. The correct logic is to attempt to create the directory and ignore errors (which is what mkdirs() does anyway), then make sure that the directory exists afterwards.