Fix pixmap cache in collection model

- Properly remove both from pixmap cache, pending art and pending cache keys when songs are deleted
- Increase default pixmap cache
- Clear pixmap cache when model is reset

src/collection/collectionmodel.cpp

@@ -125,6 +125,8 @@ CollectionModel::CollectionModel(CollectionBackend *backend, Application *app, Q
   backend_->UpdateTotalArtistCountAsync();
   backend_->UpdateTotalAlbumCountAsync();
 
+  QPixmapCache::setCacheLimit(61440);
+
 }
 
 CollectionModel::~CollectionModel() { delete root_; }
@@ -419,9 +421,21 @@ void CollectionModel::SongsDeleted(const SongList &songs) {
 
       if (node->parent != root_) parents << node->parent;
 
+      // Remove from pixmap cache
       QModelIndex idx = ItemToIndex(node->parent);
       const QString cache_key = AlbumIconPixmapCacheKey(idx);
       QPixmapCache::remove(cache_key);
+      if (pending_cache_keys_.contains(cache_key)) pending_cache_keys_.remove(cache_key);
+
+      // Remove from pending art loading
+      QMapIterator<quint64, ItemAndCacheKey> i(pending_art_);
+      while (i.hasNext()) {
+        i.next();
+        if (i.value().first == node) {
+          pending_art_.remove(i.key());
+          break;
+        }
+      }
 
       beginRemoveRows(idx, node->row, node->row);
       node->parent->Delete(node->row);
@@ -460,6 +474,22 @@ void CollectionModel::SongsDeleted(const SongList &songs) {
       else
         container_nodes_[node->container_level].remove(node->key);
 
+      // Remove from pixmap cache
+      QModelIndex idx = ItemToIndex(node->parent);
+      const QString cache_key = AlbumIconPixmapCacheKey(idx);
+      QPixmapCache::remove(cache_key);
+      if (pending_cache_keys_.contains(cache_key)) pending_cache_keys_.remove(cache_key);
+
+      // Remove from pending art loading
+      QMapIterator<quint64, ItemAndCacheKey> i(pending_art_);
+      while (i.hasNext()) {
+        i.next();
+        if (i.value().first == node) {
+          pending_art_.remove(i.key());
+          break;
+        }
+      }
+
       // It was empty - delete it
       beginRemoveRows(ItemToIndex(node->parent), node->row, node->row);
       node->parent->Delete(node->row);
@@ -567,6 +597,8 @@ void CollectionModel::AlbumCoverLoaded(const quint64 id, const QUrl &cover_url,
   }
 
   const QModelIndex idx = ItemToIndex(item);
+  if (!idx.isValid()) return;
+
   emit dataChanged(idx, idx);
 
 }
@@ -798,6 +830,8 @@ void CollectionModel::BeginReset() {
   container_nodes_[2].clear();
   divider_nodes_.clear();
   pending_art_.clear();
+  pending_cache_keys_.clear();
+  QPixmapCache::clear();
 
   root_ = new CollectionItem(this);
   root_->compilation_artist_node_ = nullptr;