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

5 files changed, 44 insertions, 70 deletions

diff --git a/test/api/custom_layer.test.cpp b/test/api/custom_layer.test.cpp
index eb1d7e0d3a..6cb148a349 100644
--- a/test/api/custom_layer.test.cpp
+++ b/test/api/custom_layer.test.cpp
@@ -34,19 +34,8 @@ void main() {
 // layer implementation because it is intended to reflect how someone using custom layers
 // might actually write their own implementation.
 
-class TestLayer {
+class TestLayer : public mbgl::style::CustomLayerHost {
 public:
-    ~TestLayer() {
-        if (program) {
-            MBGL_CHECK_ERROR(glDeleteBuffers(1, &buffer));
-            MBGL_CHECK_ERROR(glDetachShader(program, vertexShader));
-            MBGL_CHECK_ERROR(glDetachShader(program, fragmentShader));
-            MBGL_CHECK_ERROR(glDeleteShader(vertexShader));
-            MBGL_CHECK_ERROR(glDeleteShader(fragmentShader));
-            MBGL_CHECK_ERROR(glDeleteProgram(program));
-        }
-    }
-
     void initialize() {
         program = MBGL_CHECK_ERROR(glCreateProgram());
         vertexShader = MBGL_CHECK_ERROR(glCreateShader(GL_VERTEX_SHADER));
@@ -67,7 +56,7 @@ public:
         MBGL_CHECK_ERROR(glBufferData(GL_ARRAY_BUFFER, 6 * sizeof(GLfloat), triangle, GL_STATIC_DRAW));
     }
 
-    void render() {
+    void render(const mbgl::style::CustomLayerRenderParameters&) {
         MBGL_CHECK_ERROR(glUseProgram(program));
         MBGL_CHECK_ERROR(glBindBuffer(GL_ARRAY_BUFFER, buffer));
         MBGL_CHECK_ERROR(glEnableVertexAttribArray(a_pos));
@@ -75,6 +64,19 @@ public:
         MBGL_CHECK_ERROR(glDrawArrays(GL_TRIANGLE_STRIP, 0, 3));
     }
 
+    void contextLost() {}
+
+    void deinitialize() {
+         if (program) {
+                MBGL_CHECK_ERROR(glDeleteBuffers(1, &buffer));
+                MBGL_CHECK_ERROR(glDetachShader(program, vertexShader));
+                MBGL_CHECK_ERROR(glDetachShader(program, fragmentShader));
+                MBGL_CHECK_ERROR(glDeleteShader(vertexShader));
+                MBGL_CHECK_ERROR(glDeleteShader(fragmentShader));
+                MBGL_CHECK_ERROR(glDeleteProgram(program));
+            }
+    }
+
     GLuint program = 0;
     GLuint vertexShader = 0;
     GLuint fragmentShader = 0;
@@ -95,15 +97,7 @@ TEST(CustomLayer, Basic) {
     map.setLatLngZoom({ 37.8, -122.5 }, 10);
     map.getStyle().addLayer(std::make_unique<CustomLayer>(
         "custom",
-        [] (void* context) {
-            reinterpret_cast<TestLayer*>(context)->initialize();
-        },
-        [] (void* context, const CustomLayerRenderParameters&) {
-            reinterpret_cast<TestLayer*>(context)->render();
-        },
-        [] (void* context) {
-            delete reinterpret_cast<TestLayer*>(context);
-        }, new TestLayer()));
+        std::make_unique<TestLayer>()));
 
     auto layer = std::make_unique<FillLayer>("landcover", "mapbox");
     layer->setSourceLayer("landcover");
diff --git a/test/style/conversion/stringify.test.cpp b/test/style/conversion/stringify.test.cpp
index 0b2940a0e0..136f276aaf 100644
--- a/test/style/conversion/stringify.test.cpp
+++ b/test/style/conversion/stringify.test.cpp
@@ -80,23 +80,25 @@ TEST(Stringify, Filter) {
 }
 
 TEST(Stringify, CameraFunction) {
+    ASSERT_EQ(stringify(CameraFunction<float>(ExponentialStops<float> { {{0, 1}}, 1 })),
+        "[\"interpolate\",[\"linear\"],[\"zoom\"],0.0,1.0]");
     ASSERT_EQ(stringify(CameraFunction<float>(ExponentialStops<float> { {{0, 1}}, 2 })),
-        "{\"type\":\"exponential\",\"base\":2.0,\"stops\":[[0.0,1.0]]}");
+        "[\"interpolate\",[\"exponential\",2.0],[\"zoom\"],0.0,1.0]");
     ASSERT_EQ(stringify(CameraFunction<float>(IntervalStops<float> { {{0, 1}} })),
-        "{\"type\":\"interval\",\"stops\":[[0.0,1.0]]}");
+        "[\"step\",[\"zoom\"],0.0,1.0]");
 }
 
 TEST(Stringify, SourceFunction) {
     ASSERT_EQ(stringify(SourceFunction<float>("property", ExponentialStops<float> { {{0, 1}}, 2 })),
-        "{\"property\":\"property\",\"type\":\"exponential\",\"base\":2.0,\"stops\":[[0.0,1.0]]}");
+        "[\"interpolate\",[\"exponential\",2.0],[\"number\",[\"get\",\"property\"]],0.0,1.0]");
     ASSERT_EQ(stringify(SourceFunction<float>("property", IntervalStops<float> { {{0, 1}} })),
-        "{\"property\":\"property\",\"type\":\"interval\",\"stops\":[[0.0,1.0]]}");
+        "[\"step\",[\"number\",[\"get\",\"property\"]],0.0,1.0]");
     ASSERT_EQ(stringify(SourceFunction<float>("property", CategoricalStops<float> { {{CategoricalValue(true), 1}} })),
-        "{\"property\":\"property\",\"type\":\"categorical\",\"stops\":[[true,1.0]]}");
+        "[\"case\",[\"boolean\",[\"get\",\"property\"]],1.0,[\"error\"]]");
     ASSERT_EQ(stringify(SourceFunction<float>("property", IdentityStops<float> {})),
-        "{\"property\":\"property\",\"type\":\"identity\"}");
+        "[\"number\",[\"get\",\"property\"]]");
     ASSERT_EQ(stringify(SourceFunction<float>("property", IdentityStops<float> {}, 0.0f)),
-        "{\"property\":\"property\",\"type\":\"identity\",\"default\":0.0}");
+        "[\"number\",[\"get\",\"property\"]]");
 }
 
 TEST(Stringify, CompositeFunction) {
@@ -108,16 +110,17 @@ TEST(Stringify, CompositeFunction) {
             },
             2
         }, 0.0f)),
-        "{\"property\":\"property\",\"type\":\"exponential\",\"base\":2.0,"
-        "\"stops\":["
-            "[{\"zoom\":0.0,\"value\":0.0},1.0],"
-            "[{\"zoom\":1.0,\"value\":0.0},1.0]],\"default\":0.0}");
+        "[\"interpolate\","
+            "[\"linear\"],"
+            "[\"zoom\"],"
+            "0.0,[\"interpolate\",[\"exponential\",2.0],[\"number\",[\"get\",\"property\"]],0.0,1.0],"
+            "1.0,[\"interpolate\",[\"exponential\",2.0],[\"number\",[\"get\",\"property\"]],0.0,1.0]]");
 }
 
 TEST(Stringify, PropertyValue) {
     ASSERT_EQ(stringify(PropertyValue<float>(1)), "1.0");
     ASSERT_EQ(stringify(PropertyValue<float>(CameraFunction<float>(ExponentialStops<float> { {{0, 1}}, 2 }))),
-        "{\"type\":\"exponential\",\"base\":2.0,\"stops\":[[0.0,1.0]]}");
+        "[\"interpolate\",[\"exponential\",2.0],[\"zoom\"],0.0,1.0]");
 }
 
 TEST(Stringify, Layout) {
diff --git a/test/style/expression/expression.test.cpp b/test/style/expression/expression.test.cpp
index 694569695c..fe5c261be1 100644
--- a/test/style/expression/expression.test.cpp
+++ b/test/style/expression/expression.test.cpp
@@ -49,7 +49,7 @@ TEST_P(ExpressionEqualityTest, ExpressionEquality) {
         assert(!document.HasParseError());
         const JSValue* expression = &document;
         expression::ParsingContext ctx;
-        expression::ParseResult parsed = ctx.parse(conversion::Convertible(expression));
+        expression::ParseResult parsed = ctx.parseExpression(conversion::Convertible(expression));
         if (!parsed) {
             error_ = ctx.getErrors().size() > 0 ? ctx.getErrors()[0].message : "failed to parse";
         };
diff --git a/test/style/filter.test.cpp b/test/style/filter.test.cpp
index 6f261c43ec..49edcaef45 100644
--- a/test/style/filter.test.cpp
+++ b/test/style/filter.test.cpp
@@ -11,14 +11,19 @@
 using namespace mbgl;
 using namespace mbgl::style;
 
-bool filter(const char * json, const PropertyMap& featureProperties = {{}}, optional<FeatureIdentifier> featureId = {}, FeatureType featureType = FeatureType::Point, GeometryCollection featureGeometry = {}) {
+bool filter(const char * json,
+            const PropertyMap& featureProperties = {{}},
+            optional<FeatureIdentifier> featureId = {},
+            FeatureType featureType = FeatureType::Point,
+            GeometryCollection featureGeometry = {},
+            float zoom = 0.0f) {
     conversion::Error error;
     optional<Filter> filter = conversion::convertJSON<Filter>(json, error);
     EXPECT_TRUE(bool(filter));
     EXPECT_EQ(error.message, "");
     
     StubGeometryTileFeature feature { featureId, featureType, featureGeometry, featureProperties };
-    expression::EvaluationContext context = { &feature };
+    expression::EvaluationContext context = { zoom, &feature };
     
     return (*filter)(context);
 }
@@ -109,3 +114,8 @@ TEST(Filter, PropertyExpression) {
     ASSERT_TRUE(filter("[\"==\", [\"get\", \"two\"], 2]", {{"two", int64_t(2)}}));
     ASSERT_FALSE(filter("[\"==\", [\"get\", \"two\"], 4]", {{"two", int64_t(2)}}));
 }
+
+TEST(Filter, ZoomExpressionNested) {
+    ASSERT_TRUE(filter(R"(["==", ["get", "two"], ["zoom"]])", {{"two", int64_t(2)}}, {}, FeatureType::Point, {}, 2.0f));
+    ASSERT_FALSE(filter(R"(["==", ["get", "two"], ["+", ["zoom"], 1]])", {{"two", int64_t(2)}}, {}, FeatureType::Point, {}, 2.0f));
+}
diff --git a/test/tile/vector_tile.test.cpp b/test/tile/vector_tile.test.cpp
index 9d42f7ae74..cd53c7c4a4 100644
--- a/test/tile/vector_tile.test.cpp
+++ b/test/tile/vector_tile.test.cpp
@@ -65,39 +65,6 @@ TEST(VectorTile, onError) {
     EXPECT_TRUE(tile.isComplete());
 }
 
-TEST(VectorTile, Issue7615) {
-    VectorTileTest test;
-    VectorTile tile(OverscaledTileID(0, 0, 0), "source", test.tileParameters, test.tileset);
-
-    style::SymbolLayer symbolLayer("symbol", "source");
-    std::vector<SymbolInstance> symbolInstances;
-    auto symbolBucket = std::make_shared<SymbolBucket>(
-        style::SymbolLayoutProperties::PossiblyEvaluated(),
-        std::map<
-            std::string,
-            std::pair<style::IconPaintProperties::PossiblyEvaluated, style::TextPaintProperties::PossiblyEvaluated>>(),
-        16.0f, 1.0f, 0.0f, false, false, false, std::move(symbolInstances));
-    
-    // Simulate placement of a symbol layer.
-    tile.onPlacement(GeometryTile::PlacementResult {
-        {{
-            symbolLayer.getID(),
-            symbolBucket
-        }},
-        {},
-        {},
-    }, 0);
-
-    // Subsequent onLayout should not cause the existing symbol bucket to be discarded.
-    tile.onLayout(GeometryTile::LayoutResult {
-        std::unordered_map<std::string, std::shared_ptr<Bucket>>(),
-        nullptr,
-        nullptr,
-    }, 0);
-
-    EXPECT_EQ(symbolBucket.get(), tile.getBucket(*symbolLayer.baseImpl));
-}
-
 TEST(VectorTile, Issue8542) {
     VectorTileTest test;
     VectorTile tile(OverscaledTileID(0, 0, 0), "source", test.tileParameters, test.tileset);