Merge branch 'release-boba' into masterupstream/fabian-merge-v4.0.0

# Conflicts:
#	circle.yml
#	include/mbgl/style/expression/let.hpp
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/geometry/LatLngBounds.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapGestureDetector.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapKeyListener.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapboxMap.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Projection.java
#	platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Transform.java
#	platform/android/MapboxGLAndroidSDK/src/test/java/com/mapbox/mapboxsdk/geometry/LatLngBoundsTest.java
#	platform/android/MapboxGLAndroidSDKTestApp/src/main/AndroidManifest.xml
#	platform/android/gradle/dependencies.gradle
#	platform/android/src/example_custom_layer.cpp
#	platform/android/src/geojson/point.cpp
#	platform/darwin/src/NSPredicate+MGLAdditions.mm
#	platform/darwin/test/MGLExpressionTests.mm
#	platform/ios/Mapbox-iOS-SDK-nightly-dynamic.podspec
#	platform/ios/Mapbox-iOS-SDK-symbols.podspec
#	platform/ios/Mapbox-iOS-SDK.podspec
#	platform/ios/app/MBXViewController.m
#	src/mbgl/renderer/layers/render_custom_layer.cpp
#	src/mbgl/style/conversion/filter.cpp
#	src/mbgl/style/expression/interpolate.cpp
#	src/mbgl/style/expression/value.cpp
#	test/style/filter.test.cpp

1 files changed, 5 insertions, 2 deletions

diff --git a/include/mbgl/style/conversion/heatmap_color_property_value.hpp b/include/mbgl/style/conversion/heatmap_color_property_value.hpp
index e3689c524c..a4710792d2 100644
--- a/include/mbgl/style/conversion/heatmap_color_property_value.hpp
+++ b/include/mbgl/style/conversion/heatmap_color_property_value.hpp
@@ -4,11 +4,11 @@
 #include <mbgl/style/conversion.hpp>
 #include <mbgl/style/conversion/constant.hpp>
 #include <mbgl/style/conversion/function.hpp>
-#include <mbgl/style/conversion/expression.hpp>
 #include <mbgl/style/expression/value.hpp>
 #include <mbgl/style/expression/is_constant.hpp>
 #include <mbgl/style/expression/is_expression.hpp>
 #include <mbgl/style/expression/find_zoom_curve.hpp>
+#include <mbgl/style/expression/parsing_context.hpp>
 
 namespace mbgl {
 namespace style {
@@ -17,11 +17,14 @@ namespace conversion {
 template <>
 struct Converter<HeatmapColorPropertyValue> {
     optional<HeatmapColorPropertyValue> operator()(const Convertible& value, Error& error) const {
+        using namespace mbgl::style::expression;
         if (isUndefined(value)) {
             return HeatmapColorPropertyValue();
         } else if (isExpression(value)) {
-            optional<std::unique_ptr<Expression>> expression = convert<std::unique_ptr<Expression>>(value, error, expression::type::Color);
+            ParsingContext ctx(type::Color);
+            ParseResult expression = ctx.parseLayerPropertyExpression(value);
             if (!expression) {
+                error = { ctx.getCombinedErrors() };
                 return {};
             }
             assert(*expression);