also add localFile returning a QFile

python/core/qgsnetworkcontentfetcherregistry.sip.in

@@ -130,7 +130,13 @@ Create the registry for temporary downloaded files
    If the download starts immediately, it will not redownload any already fetched or currently fetching file.
 %End
 
+
     QString localPath( const QString &filePathOrUrl );
+%Docstring
+ Returns the path to a local file or to a temporary file previously fetched by the registry
+
+:param filePathOrUrl: can either be a local file path or a remote content which has previously been fetched
+%End
 
 };
 

src/core/qgsnetworkcontentfetcherregistry.cpp

@@ -70,7 +70,7 @@ const QgsFetchedContent *QgsNetworkContentFetcherRegistry::fetch( const QUrl &ur
   QObject::connect( content, &QgsFetchedContent::cancelTriggered, this, [ = ]()
   {
     QMutexLocker locker( &mMutex );
-    if ( content->mFetchingTask )
+    if ( content->mFetchingTask->canCancel() )
     {
       content->mFetchingTask->cancel();
     }
@@ -115,6 +115,37 @@ const QgsFetchedContent *QgsNetworkContentFetcherRegistry::fetch( const QUrl &ur
   return content;
 }
 
+const QFile *QgsNetworkContentFetcherRegistry::localFile( const QString &filePathOrUrl )
+{
+  QFile *file = nullptr;
+  QString path = filePathOrUrl;
+
+  if ( !QUrl::fromUserInput( filePathOrUrl ).isLocalFile() )
+  {
+    if ( mFileRegistry.contains( QUrl( path ) ) )
+    {
+      const QgsFetchedContent *content = mFileRegistry.value( QUrl( path ) );
+      if ( content->status() == QgsFetchedContent::Finished && !content->file() )
+      {
+        file = content->file();
+      }
+      else
+      {
+        // if the file is not downloaded yet or has failed, return nullptr
+      }
+    }
+    else
+    {
+      // if registry doesn't contain the URL, return nullptr
+    }
+  }
+  else
+  {
+    file = new QFile( filePathOrUrl );
+  }
+  return file;
+}
+
 QString QgsNetworkContentFetcherRegistry::localPath( const QString &filePathOrUrl )
 {
   QString path = filePathOrUrl;

src/core/qgsnetworkcontentfetcherregistry.h

@@ -147,6 +147,19 @@ class CORE_EXPORT QgsNetworkContentFetcherRegistry : public QObject
      */
     const QgsFetchedContent *fetch( const QUrl &url, const FetchingMode &fetchingMode = DownloadLater );
 
+#ifndef SIP_RUN
+
+    /**
+     * \brief Returns a QFile from a local file or to a temporary file previously fetched by the registry
+     * \param filePathOrUrl can either be a local file path or a remote content which has previously been fetched
+     */
+    const QFile *localFile( const QString &filePathOrUrl );
+#endif
+
+    /**
+     * \brief Returns the path to a local file or to a temporary file previously fetched by the registry
+     * \param filePathOrUrl can either be a local file path or a remote content which has previously been fetched
+     */
     QString localPath( const QString &filePathOrUrl );
 
   private: