From 1b8ca2772eef033edc19257ec43d924faeb397fa Mon Sep 17 00:00:00 2001
From: Oscar Mira <valldrac@molly.im>
Date: Wed, 18 Sep 2024 18:01:37 +0200
Subject: [PATCH] Fix double call to DocumentFile.getName to avoid potential
 race

---
 .../securesms/util/BackupUtil.java             | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/util/BackupUtil.java b/app/src/main/java/org/thoughtcrime/securesms/util/BackupUtil.java
index 5d2351ee46..c149258b66 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/util/BackupUtil.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/util/BackupUtil.java
@@ -155,8 +155,9 @@ private static List<BackupInfo> getAllBackupsNewestFirstApi29() {
     List<BackupInfo> backups = new ArrayList<>(files.length);
 
     for (DocumentFile file : files) {
-      if (file.isFile() && file.getName() != null && file.getName().endsWith(".backup")) {
-        long backupTimestamp = getBackupTimestamp(file.getName());
+      String backupName = file.getName();
+      if (file.isFile() && hasBackupExtension(backupName)) {
+        long backupTimestamp = getBackupTimestamp(backupName);
 
         if (backupTimestamp != -1) {
           backups.add(new BackupInfo(backupTimestamp, file.length(), file.getUri()));
@@ -169,6 +170,10 @@ private static List<BackupInfo> getAllBackupsNewestFirstApi29() {
     return backups;
   }
 
+  private static boolean hasBackupExtension(String fileName) {
+    return fileName != null && fileName.endsWith(".backup");
+  }
+
   public static @Nullable BackupInfo getBackupInfoFromSingleUri(@NonNull Context context, @NonNull Uri singleUri) throws BackupFileException {
     DocumentFile documentFile = Objects.requireNonNull(DocumentFile.fromSingleUri(context, singleUri));
 
@@ -180,7 +185,7 @@ private static List<BackupInfo> getAllBackupsNewestFirstApi29() {
     BackupFileState backupFileState = getBackupFileState(documentFile);
 
     if (backupFileState.isSuccess()) {
-      long backupTimestamp = getBackupTimestamp(Objects.requireNonNull(documentFile.getName()));
+      long backupTimestamp = getBackupTimestamp(documentFile.getName());
       return new BackupInfo(backupTimestamp, documentFile.length(), documentFile.getUri());
     } else {
       Log.w(TAG, "Could not load backup info.");
@@ -242,8 +247,9 @@ public static boolean hasBackupFiles(@NonNull Context context) {
     }
   }
 
-  private static long getBackupTimestamp(@NonNull String backupName) {
-    if (backupName.startsWith(BuildConfig.BACKUP_FILENAME) &&
+  private static long getBackupTimestamp(@Nullable String backupName) {
+    if (backupName != null &&
+        backupName.startsWith(BuildConfig.BACKUP_FILENAME) &&
         backupName.endsWith(".backup")) {
       String ts = backupName.substring(BuildConfig.BACKUP_FILENAME.length(),
                                        backupName.length() - ".backup".length());
@@ -275,7 +281,7 @@ private static BackupFileState getBackupFileState(@NonNull DocumentFile document
       return BackupFileState.NOT_FOUND;
     } else if (!documentFile.canRead()) {
       return BackupFileState.NOT_READABLE;
-    } else if (Util.isEmpty(documentFile.getName()) || !documentFile.getName().endsWith(".backup")) {
+    } else if (!hasBackupExtension(documentFile.getName())) {
       return BackupFileState.UNSUPPORTED_FILE_EXTENSION;
     } else {
       return BackupFileState.READABLE;