also move WAL file when moving database (#2583)

the WAL files come from sqlite WAL mode,
they have the same name as the database file with an extra `-wal` suffix.

according to https://sqlite.org/wal.html#the_wal_file ,
the WAL file is part of the persistent state of the database
and should be kept with the database if the database is copied or moved.

src/accounts.rs

@@ -118,6 +118,7 @@ impl Accounts {
     /// Migrate an existing account into this structure.
     pub async fn migrate_account(&self, dbfile: PathBuf) -> Result<u32> {
         let blobdir = Context::derive_blobdir(&dbfile);
+        let walfile = Context::derive_walfile(&dbfile);
 
         ensure!(
             dbfile.exists().await,
@@ -141,6 +142,7 @@ impl Accounts {
 
         let new_dbfile = account_config.dbfile().into();
         let new_blobdir = Context::derive_blobdir(&new_dbfile);
+        let new_walfile = Context::derive_walfile(&new_dbfile);
 
         let res = {
             fs::create_dir_all(&account_config.dir)
@@ -152,6 +154,11 @@ impl Accounts {
             fs::rename(&blobdir, &new_blobdir)
                 .await
                 .context("failed to rename blobdir")?;
+            if walfile.exists().await {
+                fs::rename(&walfile, &new_walfile)
+                    .await
+                    .context("failed to rename walfile")?;
+            }
             Ok(())
         };
 

src/context.rs

@@ -559,6 +559,13 @@ impl Context {
         blob_fname.push("-blobs");
         dbfile.with_file_name(blob_fname)
     }
+
+    pub fn derive_walfile(dbfile: &PathBuf) -> PathBuf {
+        let mut wal_fname = OsString::new();
+        wal_fname.push(dbfile.file_name().unwrap_or_default());
+        wal_fname.push("-wal");
+        dbfile.with_file_name(wal_fname)
+    }
 }
 
 impl InnerContext {