fix(file-list): browse up

app/src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.kt

@@ -1575,7 +1575,13 @@ class FileDisplayActivity :
 
     private fun handleRemovedFolder(syncFolderRemotePath: String?) {
         DisplayUtils.showSnackMessage(this, R.string.sync_current_folder_was_removed, syncFolderRemotePath)
-        browseToRoot()
+        fileListFragment?.let {
+            it.parentFolderFinder.getParentOnFirstParentRemoved(syncFolderRemotePath, storageManager)?.let { target ->
+                it.listDirectory(target, MainApp.isOnlyOnDevice())
+                updateActionBarTitleAndHomeButton(target)
+                file = target
+            }
+        }
     }
 
     private fun updateFileList(
@@ -1899,13 +1905,13 @@ class FileDisplayActivity :
     // endregion
 
     fun browseToRoot() {
-        val listOfFiles = this.listOfFilesFragment
-        if (listOfFiles != null) { // should never be null, indeed
+        listOfFilesFragment?.let {
             val root = storageManager.getFileByPath(OCFile.ROOT_PATH)
-            listOfFiles.resetSearchAttributes()
-            file = listOfFiles.currentFile
+            it.resetSearchAttributes()
+            file = it.currentFile
             startSyncFolderOperation(root, false)
         }
+
         binding.fabMain.setImageResource(R.drawable.ic_plus)
         resetScrollingAndUpdateActionBar()
     }

app/src/main/java/com/owncloud/android/ui/fragment/OCFileListFragment.java

@@ -80,7 +80,6 @@
 import com.owncloud.android.lib.resources.e2ee.ToggleEncryptionRemoteOperation;
 import com.owncloud.android.lib.resources.files.SearchRemoteOperation;
 import com.owncloud.android.lib.resources.files.ToggleFavoriteRemoteOperation;
-import com.owncloud.android.lib.resources.files.model.RemoteFile;
 import com.owncloud.android.lib.resources.status.E2EVersion;
 import com.owncloud.android.lib.resources.status.OCCapability;
 import com.owncloud.android.lib.resources.status.Type;
@@ -106,6 +105,7 @@
 import com.owncloud.android.ui.events.FavoriteEvent;
 import com.owncloud.android.ui.events.FileLockEvent;
 import com.owncloud.android.ui.events.SearchEvent;
+import com.owncloud.android.ui.fragment.helper.ParentFolderFinder;
 import com.owncloud.android.ui.helpers.FileOperationsHelper;
 import com.owncloud.android.ui.interfaces.OCFileListFragmentInterface;
 import com.owncloud.android.ui.preview.PreviewImageFragment;
@@ -124,7 +124,6 @@
 import org.greenrobot.eventbus.Subscribe;
 import org.greenrobot.eventbus.ThreadMode;
 
-import java.io.File;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
@@ -228,6 +227,7 @@ public class OCFileListFragment extends ExtendedListFragment implements
     protected String mLimitToMimeType;
     private FloatingActionButton mFabMain;
     public static boolean isMultipleFileSelectedForCopyOrMove = false;
+    public final ParentFolderFinder parentFolderFinder = new ParentFolderFinder();
 
     private static final Intent scanIntentExternalApp = new Intent("org.fairscan.app.action.SCAN_TO_PDF");
 
@@ -1019,7 +1019,6 @@ private void updateSortAndGridMenuItems() {
         }
     }
 
-
     /**
      * Call this, when the user presses the up button.
      * <p>
@@ -1029,62 +1028,27 @@ private void updateSortAndGridMenuItems() {
      * return Count of folder levels browsed up.
      */
     public int onBrowseUp() {
-        if (mFile == null) {
+        if (mFile == null || mFile.isRootDirectory()) {
+            return 0;
+        }
+
+        final var result = parentFolderFinder.getParent(mFile, mContainerActivity.getStorageManager());
+        OCFile target = result.getSecond();
+
+        if (target == null) {
+            Log_OC.e(TAG, "onBrowseUp: could not resolve parent, staying put");
             return 0;
         }
 
-        Pair<Integer, OCFile> result = getPreviousFile();
-        mFile = result.second;
+        mFile = target;
         setFileDepth(mFile);
 
-        // since on browse down sets it to the false, browse up should set back to true if current search type is not NO_SEARCH
         if (mFile.isRootDirectory() && currentSearchType != NO_SEARCH) {
             searchFragment = true;
         }
 
         updateFileList();
-        return result.first;
-    }
-
-    private Pair<Integer, OCFile> getPreviousFile() {
-        if (mFile == null) {
-            return new Pair<>(0, null);
-        }
-
-        FileDataStorageManager storageManager = mContainerActivity.getStorageManager();
-        int moveCount = 0;
-        String parentPath;
-        OCFile parentDir;
-
-        if (mFile.getParentId() != FileDataStorageManager.ROOT_PARENT_ID) {
-            parentPath = new File(mFile.getRemotePath()).getParent();
-            parentPath = ensureTrailingSeparator(parentPath);
-            parentDir = storageManager.getFileByPath(parentPath);
-            moveCount++;
-        } else {
-            parentDir = storageManager.getFileByPath(ROOT_PATH);
-            parentPath = ROOT_PATH;
-        }
-
-        // Keep going up until we find a valid folder
-        while (parentDir == null && !ROOT_PATH.equals(parentPath)) {
-            parentPath = new File(parentPath).getParent();
-            if (parentPath == null) {
-                parentPath = ROOT_PATH; // fallback to root
-            }
-            parentPath = ensureTrailingSeparator(parentPath);
-            parentDir = storageManager.getFileByPath(parentPath);
-            moveCount++;
-        }
-
-        return new Pair<>(moveCount, parentDir);
-    }
-
-    private String ensureTrailingSeparator(String path) {
-        if (path == null) {
-            return ROOT_PATH;
-        }
-        return path.endsWith(OCFile.PATH_SEPARATOR) ? path : path + OCFile.PATH_SEPARATOR;
+        return result.getFirst();
     }
 
     private void updateFileList() {

app/src/main/java/com/owncloud/android/ui/fragment/helper/ParentFolderFinder.kt

@@ -0,0 +1,132 @@
+/*
+ * Nextcloud - Android Client
+ *
+ * SPDX-FileCopyrightText: 2026 Alper Ozturk <alper.ozturk@nextcloud.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+package com.owncloud.android.ui.fragment.helper
+
+import com.owncloud.android.datamodel.FileDataStorageManager
+import com.owncloud.android.datamodel.OCFile
+import com.owncloud.android.lib.common.utils.Log_OC
+
+@Suppress("ReturnCount")
+class ParentFolderFinder {
+    companion object {
+        private const val TAG = "ParentFolderFinder"
+    }
+
+    /**
+     * User tries to move up but parent folder was deleted thus parent of parent
+     * will be used as destination else ROOT directory
+     */
+    fun getParentOnFirstParentRemoved(path: String?, storageManager: FileDataStorageManager?): OCFile? {
+        if (storageManager == null) {
+            Log_OC.e(TAG, "StorageManager is null")
+            return null
+        }
+
+        if (path.isNullOrEmpty() || path == OCFile.ROOT_PATH) {
+            Log_OC.w(TAG, "Path is null, empty, or already at root. Falling back to ROOT.")
+            return storageManager.getFileByEncryptedRemotePath(OCFile.ROOT_PATH)
+        }
+
+        return walkUpByPath(path, storageManager).second
+    }
+
+    fun getParent(file: OCFile?, storageManager: FileDataStorageManager?): Pair<Int, OCFile?> {
+        if (file == null || file.isRootDirectory) {
+            Log_OC.e(TAG, "File is null or already at root")
+            return 0 to file
+        }
+
+        if (storageManager == null) {
+            Log_OC.e(TAG, "StorageManager is null")
+            return 0 to file
+        }
+
+        // id based lookup
+        val parentId = file.parentId
+        if (parentId > FileDataStorageManager.ROOT_PARENT_ID && parentId != file.fileId) {
+            storageManager.getFileById(parentId)?.let { parentById ->
+                if (parentById.isFolder) {
+                    return 1 to parentById
+                }
+            }
+
+            Log_OC.w(TAG, "ID lookup missed for parentId=$parentId, falling back to path walk")
+        }
+
+        // path-based walk up
+        return walkUpByPath(file.remotePath, storageManager)
+    }
+
+    /**
+     * Walks the remote path upward one segment at a time until a valid folder
+     * is found in the DB, or we reach root.
+     */
+    private fun walkUpByPath(initialPath: String?, storageManager: FileDataStorageManager): Pair<Int, OCFile?> {
+        var path = initialPath
+        var moveCount = 0
+
+        while (!path.isNullOrEmpty() && path != OCFile.ROOT_PATH) {
+            val parentPath = resolveParentPath(path)
+            moveCount++
+
+            if (parentPath == null) {
+                Log_OC.w(TAG, "Failed to resolve parent path for $path, fallback to root")
+                break
+            }
+
+            // Check if this resolved parent exists in DB
+            storageManager.getFileByEncryptedRemotePath(parentPath)?.let { candidate ->
+                if (candidate.isFolder) {
+                    return moveCount to candidate
+                }
+            }
+
+            if (parentPath == OCFile.ROOT_PATH) {
+                Log_OC.w(TAG, "Root path reached but not found in DB loop, forcing fallback")
+                break
+            }
+
+            // Move up one more level for the next iteration
+            path = parentPath
+        }
+
+        // fallback to root
+        val root = storageManager.getFileByEncryptedRemotePath(OCFile.ROOT_PATH)
+        return moveCount to root
+    }
+
+    /**
+     * Returns the parent path of `path` with a guaranteed trailing "/",
+     * or `null` if `path` is already root or invalid.
+     *
+     *
+     * Correctly handles paths with or without a trailing separator, so both
+     * "/Foo/Bar" and "/Foo/Bar/" return "/Foo/".
+     */
+    private fun resolveParentPath(path: String?): String? {
+        if (path.isNullOrEmpty() || path == OCFile.ROOT_PATH) {
+            return null
+        }
+
+        // Strip trailing "/" before computing parent
+        val normalized = if (path.endsWith(OCFile.PATH_SEPARATOR)) {
+            path.substring(0, path.length - 1)
+        } else {
+            path
+        }
+
+        val lastSep = normalized.lastIndexOf(OCFile.PATH_SEPARATOR)
+        if (lastSep <= 0) {
+            Log_OC.w(TAG, "No separator found, or only one at the start")
+            return OCFile.ROOT_PATH
+        }
+
+        // e.g. "/Foo/Bar" → "/Foo/"
+        return normalized.substring(0, lastSep + 1)
+    }
+}