fix: GeometryBuffer.startLine()

- *always* set end marker

vtm/src/org/oscim/core/GeometryBuffer.java

@@ -177,8 +177,7 @@ public class GeometryBuffer {
 		setOrCheckMode(GeometryType.LINE);
 
 		// ignore
-		if (index[indexPos] == 0)
-			return this;
+		if (index[indexPos] > 0) {
 
 			// start next
 			if ((index[0] >= 0) && (++indexPos >= index.length))
@@ -186,6 +185,7 @@ public class GeometryBuffer {
 
 			// initialize with zero points
 			index[indexPos] = 0;
+		}
 
 		// set new end marker
 		if (index.length > indexPos + 1)