From 52b8911e0e9c89fe99b497436d3f48118cb7777a Mon Sep 17 00:00:00 2001
From: Adrian Cojocaru <adrian.cojocaru92@yahoo.com>
Date: Tue, 9 Dec 2025 21:08:56 +0200
Subject: [PATCH] Fix pure virtual function call v2 (#3996)

---
 src/mbgl/tile/vector_mlt_tile.cpp |  3 +++
 src/mbgl/tile/vector_mlt_tile.hpp |  2 +-
 src/mbgl/tile/vector_mvt_tile.cpp |  3 +++
 src/mbgl/tile/vector_mvt_tile.hpp |  2 +-
 src/mbgl/tile/vector_tile.cpp     | 12 ++++--------
 src/mbgl/tile/vector_tile.hpp     |  6 ++++--
 6 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/mbgl/tile/vector_mlt_tile.cpp b/src/mbgl/tile/vector_mlt_tile.cpp
index a288c57e3..0df2136bb 100644
--- a/src/mbgl/tile/vector_mlt_tile.cpp
+++ b/src/mbgl/tile/vector_mlt_tile.cpp
@@ -16,6 +16,9 @@ VectorMLTTile::VectorMLTTile(const OverscaledTileID& id_,
     : VectorTile(id_, std::move(sourceID_), parameters_, tileset_, observer_) {}
 
 VectorMLTTile::~VectorMLTTile() {
+    // this needs to be explicitly deleted in the most-derived destructor
+    loader.reset();
+
     // Don't rely on `~TileLoader` to close, it's not safe to call there.
     // We're still calling a virtual method from a destructor, so any overrides will not be called.
     GeometryTile::cancel();
diff --git a/src/mbgl/tile/vector_mlt_tile.hpp b/src/mbgl/tile/vector_mlt_tile.hpp
index 959f9c24a..e4a8fa9dd 100644
--- a/src/mbgl/tile/vector_mlt_tile.hpp
+++ b/src/mbgl/tile/vector_mlt_tile.hpp
@@ -9,7 +9,7 @@ namespace mbgl {
 class Tileset;
 class TileParameters;
 
-class VectorMLTTile : public VectorTile {
+class VectorMLTTile final : public VectorTile {
 public:
     VectorMLTTile(const OverscaledTileID&,
                   std::string sourceID,
diff --git a/src/mbgl/tile/vector_mvt_tile.cpp b/src/mbgl/tile/vector_mvt_tile.cpp
index eb01ce40e..1a8e64259 100644
--- a/src/mbgl/tile/vector_mvt_tile.cpp
+++ b/src/mbgl/tile/vector_mvt_tile.cpp
@@ -16,6 +16,9 @@ VectorMVTTile::VectorMVTTile(const OverscaledTileID& id_,
     : VectorTile(id_, std::move(sourceID_), parameters_, tileset_, observer_) {}
 
 VectorMVTTile::~VectorMVTTile() {
+    // this needs to be explicitly deleted in the most-derived destructor
+    loader.reset();
+
     // Don't rely on `~TileLoader` to close, it's not safe to call there.
     // We're still calling a virtual method from a destructor, so any overrides will not be called.
     GeometryTile::cancel();
diff --git a/src/mbgl/tile/vector_mvt_tile.hpp b/src/mbgl/tile/vector_mvt_tile.hpp
index d43c6bc26..fedf1f5b8 100644
--- a/src/mbgl/tile/vector_mvt_tile.hpp
+++ b/src/mbgl/tile/vector_mvt_tile.hpp
@@ -9,7 +9,7 @@ namespace mbgl {
 class Tileset;
 class TileParameters;
 
-class VectorMVTTile : public VectorTile {
+class VectorMVTTile final : public VectorTile {
 public:
     VectorMVTTile(const OverscaledTileID&,
                   std::string sourceID,
diff --git a/src/mbgl/tile/vector_tile.cpp b/src/mbgl/tile/vector_tile.cpp
index 01c5d5ba4..90c14d6e4 100644
--- a/src/mbgl/tile/vector_tile.cpp
+++ b/src/mbgl/tile/vector_tile.cpp
@@ -13,20 +13,16 @@ VectorTile::VectorTile(const OverscaledTileID& id_,
                        const Tileset& tileset,
                        TileObserver* observer_)
     : GeometryTile(id_, std::move(sourceID_), parameters_, observer_),
-      loader(*this, id_, parameters_, tileset) {}
+      loader(std::make_unique<TileLoader<VectorTile>>(*this, id_, parameters_, tileset)) {}
 
-VectorTile::~VectorTile() {
-    // Don't rely on `~TileLoader` to close, it's not safe to call there.
-    // We're still calling a virtual method from a destructor, so any overrides will not be called.
-    GeometryTile::cancel();
-}
+VectorTile::~VectorTile() {}
 
 void VectorTile::setNecessity(TileNecessity necessity) {
-    loader.setNecessity(necessity);
+    loader->setNecessity(necessity);
 }
 
 void VectorTile::setUpdateParameters(const TileUpdateParameters& params) {
-    loader.setUpdateParameters(params);
+    loader->setUpdateParameters(params);
 }
 
 void VectorTile::setMetadata(std::optional<Timestamp> modified_, std::optional<Timestamp> expires_) {
diff --git a/src/mbgl/tile/vector_tile.hpp b/src/mbgl/tile/vector_tile.hpp
index 0364c52c8..cd9188e23 100644
--- a/src/mbgl/tile/vector_tile.hpp
+++ b/src/mbgl/tile/vector_tile.hpp
@@ -23,8 +23,10 @@ public:
 
     virtual void setData(const std::shared_ptr<const std::string>&) = 0;
 
-private:
-    TileLoader<VectorTile> loader;
+protected:
+    // this needs to be explicitly deleted in the most-derived destructor
+    // see `~VectorMVTTile`
+    std::unique_ptr<TileLoader<VectorTile>> loader;
 };
 
 } // namespace mbgl