Fix a couple issues with saving files in the snap / flatpak packages

- Copy the temp file instead of renaming, which doesn't work when the temp folder is on a different volume
- Use the application's data folder for the backup file, which is more reliable (we also use this for auto backup) than the temp folder

Fixes: #498

CHANGELOG.md

@@ -13,7 +13,8 @@ Thanks to the following contributors who worked on this release:
 
 ### Fixed
 - Fixed AppStream validation issues in `xdg/powertabeditor.metainfo.xml`
-- Fixed a bug which could prevent barlines from being deleted
+- Fixed a bug which could prevent barlines from being deleted (#496)
+- Fixed errors with saving files in the Snap or Flatpak packages (#498)
 
 ## [2.0.20] - 2024-11-03
 

source/app/powertabeditor.cpp

@@ -411,7 +411,7 @@ bool PowerTabEditor::saveFile(int doc_index, QString path)
 
     try
     {
-        myFileFormatManager->exportFile(doc.getScore(), path_str, *format);
+        myFileFormatManager->exportFile(doc.getScore(), path_str, Paths::getBackupDir(), *format);
     }
     catch (const std::exception &e)
     {

source/dialogs/bulkconverterdialog.cpp

@@ -58,7 +58,7 @@ convertFile(const std::filesystem::path &src, const std::filesystem::path &dst,
 
     try
     {
-        ffm->exportFile(score, dst, export_format);
+        ffm->exportFile(score, dst, Paths::getBackupDir(), export_format);
     }
     catch (const std::exception &)
     {

source/formats/fileformatmanager.cpp

@@ -109,20 +109,27 @@ std::string FileFormatManager::exportFileFilter() const
     return filter;
 }
 
-void FileFormatManager::exportFile(const Score &score,
-                                   const std::filesystem::path &filename,
-                                   const FileFormat &format)
+void
+FileFormatManager::exportFile(const Score &score, const std::filesystem::path &filename,
+                              const std::filesystem::path &backup_folder, const FileFormat &format)
 {
     // Write to a temporary file and then swap, to avoid data loss if e.g. the exporter crashes.
-    std::filesystem::path temp_file = std::filesystem::temp_directory_path() / filename.filename();
+    std::filesystem::create_directories(backup_folder);
+    std::filesystem::path temp_file = backup_folder / filename.filename();
     temp_file += ".new";
 
     for (auto &exporter : myExporters)
     {
         if (exporter->fileFormat() == format)
         {
             exporter->save(temp_file, score);
-            std::filesystem::rename(temp_file, filename);
+
+            // Note that filesystem::rename() doesn't work if the backup folder is on a different
+            // volume, so just copy.
+            std::filesystem::copy(temp_file, filename,
+                                  std::filesystem::copy_options::overwrite_existing);
+            std::filesystem::remove(temp_file);
+
             return;
         }
     }

source/formats/fileformatmanager.h

@@ -53,7 +53,7 @@ class FileFormatManager
     /// Exports the given score to a file.
     /// @throws std::exception
     void exportFile(const Score &score, const std::filesystem::path &filename,
-                    const FileFormat &format);
+                    const std::filesystem::path &backup_folder, const FileFormat &format);
 
     // Checks to see if there is an importer for the designated extension
     bool extensionImportSupported(const std::string& extension) const;