label_position on lines should take the middle point to preserve previous behavior before move to path type geometries - patch from Ldp - closes #740 and #668

AUTHORS

@@ -58,6 +58,7 @@ Patches
  - Philipp Spitzer
  - Dave Stubbs
  - River Tarnell
+ - Lennard voor den Dag
  - Shaun Walbridge
  - Leslie Wu
   

include/mapnik/geometry.hpp

@@ -181,6 +181,12 @@ public:
 
     void label_position(double *x, double *y) const
     {
+        if (type_ == LineString || type_ == MultiLineString)
+        {
+            middle_point(x,y);
+            return;
+        }
+
         unsigned size = cont_.size();
         if (size < 3) 
         {