[core] Restored shape annotation z-order

Shapes are once again always added to the top z-index.

Fixes #5691.

Cherry-picked from 74fe96d2617f870206ff358d7dfcafccf4e109bc.

5 files changed, 24 insertions, 2 deletions

diff --git a/platform/ios/CHANGELOG.md b/platform/ios/CHANGELOG.md
index 6c08b357aa..d8aa664090 100644
--- a/platform/ios/CHANGELOG.md
+++ b/platform/ios/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 Mapbox welcomes participation and contributions from everyone.  Please read [CONTRIBUTING.md](../../CONTRIBUTING.md) to get started.
 
+## master
+
+* Fixed an issue causing overlapping polylines and polygons to be drawn in undefined z-order. Shapes are always drawn in the order they are added to the map, from the oldest on the bottom to the newest on the top. ([#5710](https://github.com/mapbox/mapbox-gl-native/pull/5710))
+
 ## 3.3.0
 
 ### Styles and data
diff --git a/platform/macos/CHANGELOG.md b/platform/macos/CHANGELOG.md
index cc2b3b8d44..a92e9f7656 100644
--- a/platform/macos/CHANGELOG.md
+++ b/platform/macos/CHANGELOG.md
@@ -1,6 +1,7 @@
 # Changelog for Mapbox macOS SDK
 
 ## master
+* Fixed an issue causing overlapping polylines and polygons to be drawn in undefined z-order. Shapes are always drawn in the order they are added to the map, from the oldest on the bottom to the newest on the top. ([#5710](https://github.com/mapbox/mapbox-gl-native/pull/5710))
 * Replaced the wireframe debug mask with an overdraw visualization debug mask to match Mapbox GL JS’s overdraw inspector. ([#5403](https://github.com/mapbox/mapbox-gl-native/pull/5403))
 * Improved the design of the generated API documentation. ([#5306](https://github.com/mapbox/mapbox-gl-native/pull/5306))
 
diff --git a/src/mbgl/annotation/annotation_manager.hpp b/src/mbgl/annotation/annotation_manager.hpp
index 73907e10c8..7e0cf3a394 100644
--- a/src/mbgl/annotation/annotation_manager.hpp
+++ b/src/mbgl/annotation/annotation_manager.hpp
@@ -58,8 +58,10 @@ private:
     AnnotationID nextID = 0;
 
     using SymbolAnnotationTree = boost::geometry::index::rtree<std::shared_ptr<const SymbolAnnotationImpl>, boost::geometry::index::rstar<16, 4>>;
-    using SymbolAnnotationMap = std::unordered_map<AnnotationID, std::shared_ptr<SymbolAnnotationImpl>>;
-    using ShapeAnnotationMap = std::unordered_map<AnnotationID, std::unique_ptr<ShapeAnnotationImpl>>;
+    // Unlike std::unordered_map, std::map is guaranteed to sort by AnnotationID, ensuring that older annotations are below newer annotations.
+    // <https://github.com/mapbox/mapbox-gl-native/issues/5691>
+    using SymbolAnnotationMap = std::map<AnnotationID, std::shared_ptr<SymbolAnnotationImpl>>;
+    using ShapeAnnotationMap = std::map<AnnotationID, std::unique_ptr<ShapeAnnotationImpl>>;
 
     SymbolAnnotationTree symbolTree;
     SymbolAnnotationMap symbolAnnotations;
diff --git a/test/api/annotations.cpp b/test/api/annotations.cpp
index 60d7db6baa..552a386f96 100644
--- a/test/api/annotations.cpp
+++ b/test/api/annotations.cpp
@@ -68,6 +68,21 @@ TEST(Annotations, FillAnnotation) {
     test.checkRendering("fill_annotation");
 }
 
+TEST(Annotations, OverlappingFillAnnotation) {
+    AnnotationTest test;
+
+    Polygon<double> polygon = {{ {{ { 0, 0 }, { 0, 45 }, { 45, 45 }, { 45, 0 } }} }};
+    FillAnnotation underlaidAnnotation { polygon };
+    underlaidAnnotation.color = { { 0, 255, 0, 1 } };
+    FillAnnotation overlaidAnnotation { polygon };
+    overlaidAnnotation.color = { { 255, 0, 0, 1 } };
+
+    test.map.setStyleJSON(util::read_file("test/fixtures/api/empty.json"));
+    test.map.addAnnotation(underlaidAnnotation);
+    test.map.addAnnotation(overlaidAnnotation);
+    test.checkRendering("overlapping_fill_annotation");
+}
+
 TEST(Annotations, StyleSourcedShapeAnnotation) {
     AnnotationTest test;
 
diff --git a/test/fixtures/annotations/overlapping_fill_annotation/expected.png b/test/fixtures/annotations/overlapping_fill_annotation/expected.png
new file mode 100644
index 0000000000..09f48081a8
--- /dev/null
+++ b/test/fixtures/annotations/overlapping_fill_annotation/expected.png