Merge pull request #1237 from mapbox/1237-text-font-function

404 errors when style uses functions for text-font

src/mbgl/renderer/symbol_bucket.cpp

@@ -45,8 +45,8 @@ std::vector<SymbolFeature> SymbolBucket::processFeatures(const GeometryTileLayer
                                                          const FilterExpression& filter,
                                                          GlyphStore &glyphStore,
                                                          const Sprite &sprite) {
-    const bool has_text = layout.text.field.size();
-    const bool has_icon = layout.icon.image.size();
+    const bool has_text = !layout.text.field.empty() && !layout.text.font.empty();
+    const bool has_icon = !layout.icon.image.empty();
 
     std::vector<SymbolFeature> features;
 

src/mbgl/style/style_layout.hpp

@@ -61,7 +61,7 @@ public:
     struct {
         RotationAlignmentType rotation_alignment = RotationAlignmentType::Viewport;
         std::string field;
-        std::string font;
+        std::string font = "Open Sans Regular, Arial Unicode MS Regular";
         float max_size = 16.0f;
         float max_width = 15.0f /* em */;
         float line_height = 1.2f /* em */;