3 files changed, 61 insertions, 4 deletions

diff --git a/launcher/FileSystem.cpp b/launcher/FileSystem.cpp
index 6de20de6..3837d75f 100644
--- a/launcher/FileSystem.cpp
+++ b/launcher/FileSystem.cpp
@@ -454,4 +454,47 @@ bool createShortCut(QString location, QString dest, QStringList args, QString na
     return false;
 #endif
 }
+
+QStringList listFolderPaths(QDir root)
+{
+    auto createAbsPath = [](QFileInfo const& entry) { return FS::PathCombine(entry.path(), entry.fileName()); };
+
+    QStringList entries;
+
+    root.refresh();
+    for (auto entry : root.entryInfoList(QDir::Filter::Files)) {
+        entries.append(createAbsPath(entry));
+    }
+
+    for (auto entry : root.entryInfoList(QDir::Filter::AllDirs | QDir::Filter::NoDotAndDotDot)) {
+        entries.append(listFolderPaths(createAbsPath(entry)));
+    }
+
+    return entries;
+}
+
+bool overrideFolder(QString overwritten_path, QString override_path)
+{
+    if (!FS::ensureFolderPathExists(overwritten_path))
+        return false;
+
+    QStringList paths_to_override;
+    QDir root_override (override_path);
+    for (auto file : listFolderPaths(root_override)) {
+        QString destination = file;
+        destination.replace(override_path, overwritten_path);
+
+        qDebug() << QString("Applying override %1 in %2").arg(file, destination);
+
+        if (QFile::exists(destination))
+            QFile::remove(destination);
+        if (!QFile::rename(file, destination)) {
+            qCritical() << QString("Failed to apply override from %1 to %2").arg(file, destination);
+            return false;
+        }
+    }
+
+    return true;
+}
+
 }
diff --git a/launcher/FileSystem.h b/launcher/FileSystem.h
index 8f6e8b48..bc942ab3 100644
--- a/launcher/FileSystem.h
+++ b/launcher/FileSystem.h
@@ -124,4 +124,8 @@ QString getDesktopDir();
 // call it *name* and assign it the icon *icon*
 // return true if operation succeeded
 bool createShortCut(QString location, QString dest, QStringList args, QString name, QString iconLocation);
+
+// Overrides one folder with the contents of another, preserving items exclusive to the first folder
+// Equivalent to doing QDir::rename, but allowing for overrides
+bool overrideFolder(QString overwritten_path, QString override_path);
 }
diff --git a/launcher/InstanceImportTask.cpp b/launcher/InstanceImportTask.cpp
index 1ccf7ffc..3dcd92c8 100644
--- a/launcher/InstanceImportTask.cpp
+++ b/launcher/InstanceImportTask.cpp
@@ -696,16 +696,26 @@ void InstanceImportTask::processModrinth()
         emitFailed(tr("Could not understand pack index:\n") + e.cause());
         return;
     }
+    
+    auto mcPath = FS::PathCombine(m_stagingPath, ".minecraft");
 
-    QString overridePath = FS::PathCombine(m_stagingPath, "overrides");
-    if (QFile::exists(overridePath)) {
-        QString mcPath = FS::PathCombine(m_stagingPath, ".minecraft");
-        if (!QFile::rename(overridePath, mcPath)) {
+    auto override_path = FS::PathCombine(m_stagingPath, "overrides");
+    if (QFile::exists(override_path)) {
+        if (!QFile::rename(override_path, mcPath)) {
             emitFailed(tr("Could not rename the overrides folder:\n") + "overrides");
             return;
         }
     }
 
+    // Do client overrides
+    auto client_override_path = FS::PathCombine(m_stagingPath, "client-overrides");
+    if (QFile::exists(client_override_path)) {
+        if (!FS::overrideFolder(mcPath, client_override_path)) {
+            emitFailed(tr("Could not rename the client overrides folder:\n") + "client overrides");
+            return;
+        }
+    }
+
     QString configPath = FS::PathCombine(m_stagingPath, "instance.cfg");
     auto instanceSettings = std::make_shared<INISettingsObject>(configPath);
     MinecraftInstance instance(m_globalSettings, instanceSettings, m_stagingPath);