Add visual test for point placement marker on lines (#1604)

tests/visual_tests/data/marker-on-line.csv

@@ -0,0 +1,2 @@
+i|wkt
+1|LINESTRING(-10  0, 0 20, 10 0, 15 5)

tests/visual_tests/styles/marker-on-line.xml

@@ -0,0 +1,21 @@
+<Map>
+<Style name="line" filter-mode="first" >
+  <Rule>
+    <LineSymbolizer stroke="#000000" />
+  </Rule>
+</Style>
+<Style name="point-placement" filter-mode="first" >
+  <Rule>
+    <MarkersSymbolizer placement="point" marker-type="ellipse" fill="blue" />
+  </Rule>
+</Style>
+<Layer name="carto_tests">
+    <StyleName>line</StyleName>
+    <StyleName>point-placement</StyleName>
+    <Datasource>
+       <Parameter name="type">csv</Parameter>
+       <Parameter name="file">../data/marker-on-line.csv</Parameter>
+       <Parameter name="separator">|</Parameter>
+    </Datasource>
+  </Layer>
+</Map>

tests/visual_tests/test.py

@@ -29,6 +29,8 @@ files = [
     {'name': "lines-shield", 'sizes': sizes_few_square},
     {'name': "marker-multi-policy", 'sizes':[(600,400)],
         'bbox': mapnik.Box2d(0, 0, 190, 180)},
+    {'name': "marker-on-line", 'sizes':[(600,400)],
+        'bbox': mapnik.Box2d(-10, 0, 15, 20)},
     {'name': "whole-centroid", 'sizes':[(600,400)],
         'bbox': mapnik.Box2d(736908, 4390316, 2060771, 5942346)},
     {'name': "simple-E"},