close cartopy#1782, change LineString facecolor to None

Author: smartlixx

lib/cartopy/mpl/geoaxes.py

@@ -753,6 +753,20 @@ def add_geometries(self, geoms, crs, **kwargs):
 
         """
         styler = kwargs.pop('styler', None)
+        has_LineString = False
+        try:
+            for g in iter(tuple(geoms)):
+                if isinstance(g, sgeom.LineString):
+                    has_LineString = True
+                    break
+        except:
+            if isinstance(geoms, sgeom.LineString):
+                has_LineString = True
+
+        if has_LineString:
+            kwargs['facecolor'] = 'none'
+            if 'edgecolor' not in kwargs or kwargs['edgecolor'] == 'face':
+                kwargs['edgecolor'] = mpl.rcParams['patch.edgecolor']
         feature = cartopy.feature.ShapelyFeature(geoms, crs, **kwargs)
         return self.add_feature(feature, styler=styler)