renderer/paint: fixed a mismatched reference count.

This correction ensures a consistent use of 'ref' and 'unref' for paints to release memory properly.
The memory leak occurred when a picture was not pushed to a valid canvas.

This issue was reported by the unit-test memory sanitizer.

src/loaders/lottie/tvgLottieLoader.cpp

@@ -304,6 +304,7 @@ unique_ptr<Paint> LottieLoader::paint()
 {
     this->done();
     if (!comp) return nullptr;
+    comp->initiated = true;
     return cast<Paint>(comp->scene);
 }
 

src/loaders/lottie/tvgLottieModel.cpp

@@ -158,6 +158,8 @@ int32_t LottieLayer::remap(int32_t frameNo)
 
 LottieComposition::~LottieComposition()
 {
+    if (!initiated) delete(scene);
+
     delete(root);
     free(version);
     free(name);

src/loaders/lottie/tvgLottieModel.h

@@ -585,6 +585,7 @@ struct LottieComposition
     float frameRate;
     Array<LottieObject*> assets;
     Array<LottieInterpolator*> interpolators;
+    bool initiated = false;
 };
 
 #endif //_TVG_LOTTIE_MODEL_H_

src/renderer/tvgAnimation.cpp

@@ -36,12 +36,12 @@ struct Animation::Impl
     Impl()
     {
         picture = Picture::gen().release();
-        static_cast<Paint*>(picture)->pImpl->ref();
+        PP(picture)->ref();
     }
 
     ~Impl()
     {
-        if (static_cast<Paint*>(picture)->pImpl->unref() == 0) {
+        if (PP(picture)->unref() == 0) {
             delete(picture);
         }
     }

src/renderer/tvgCanvas.h

@@ -53,6 +53,7 @@ struct Canvas::Impl
 
         auto p = paint.release();
         if (!p) return Result::MemoryCorruption;
+        PP(p)->ref();
         paints.push_back(p);
 
         return update(p, true);
@@ -66,8 +67,9 @@ struct Canvas::Impl
         //Free paints
         if (free) {
             for (auto paint : paints) {
-                if (paint->pImpl->dispose(*renderer)) {
+                P(paint)->unref();
-                    if (paint->pImpl->unref() == 0) delete(paint);
+                if (paint->pImpl->dispose(*renderer) && P(paint)->refCnt == 0) {
+                    delete(paint);
                 }
             }
             paints.clear();

src/renderer/tvgPaint.h

@@ -68,7 +68,7 @@ namespace tvg
         uint8_t ctxFlag = ContextFlag::Invalid;
         uint8_t id;
         uint8_t opacity = 255;
-        uint8_t refCnt = 1;
+        uint8_t refCnt = 0;
 
         ~Impl()
         {

src/renderer/tvgScene.cpp

@@ -55,6 +55,7 @@ Result Scene::push(unique_ptr<Paint> paint) noexcept
 {
     auto p = paint.release();
     if (!p) return Result::MemoryCorruption;
+    PP(p)->ref();
     pImpl->paints.push_back(p);
 
     return Result::Success;

src/renderer/tvgScene.h

@@ -220,7 +220,9 @@ struct Scene::Impl
         auto dup = ret.get()->pImpl;
 
         for (auto paint : paints) {
-            dup->paints.push_back(paint->duplicate());
+            auto cdup = paint->duplicate();
+            P(cdup)->ref();
+            dup->paints.push_back(cdup);
         }
 
         return ret.release();
@@ -231,8 +233,8 @@ struct Scene::Impl
         auto dispose = renderer ? true : false;
 
         for (auto paint : paints) {
-            if (dispose) free &= paint->pImpl->dispose(*renderer);
+            if (dispose) free &= P(paint)->dispose(*renderer);
-            if (free) delete(paint);
+            if (P(paint)->unref() == 0 && free) delete(paint);
         }
         paints.clear();
         renderer = nullptr;