[Bug] Tauri v1 migration silently discards all historical session data in workspace .dat files #27431

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1. github-actions

   assigned

   Hona

   on May 14, 2026
2. 21pounder commented on May 14, 2026

   

   21pounder

   on May 14, 2026

   Contributor

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   I looked into this and can confirm the root cause.

   Root cause

   The migration code in packages/desktop/src/main/migrate.ts uses the old .dat filename directly as the electron-store name:

   // migrate.ts:51
   const storeName = filename === "opencode.settings.dat" ? "opencode.settings" : filename

   So opencode.workspace.Qzpc.vtnkm7.dat gets migrated into a store named opencode.workspace.Qzpc.vtnkm7.dat.

   But the app never reads that store. The workspace store name is generated in packages/app/src/utils/persist.ts using a completely different scheme:

   // persist.ts:337-341
   function workspaceStorage(dir: string) {
     const head = (dir.slice(0, 12) || "workspace").replace(/[^a-zA-Z0-9._-]/g, "-")
     const sum = checksum(dir) ?? "0"
     return `opencode.workspace.${head}.${sum}.dat`
   }
   // called with pathKey(dir), e.g. "C:/" → head="C--", giving "opencode.workspace.C--.hmddcc.dat"

   The old Tauri app encoded the workspace path as base64 in the filename (Qzpc = base64 of C:\). The new Electron app uses pathKey(dir) + FNV checksum. These two schemes produce different filenames for the same workspace, so the migrated data lands in a store the app never opens.

   The session keys (session:ses_xxx:prompt, etc.) appear in skipped in the log because the migration ran against the correct old file, but wrote into the wrong target store — and on a second run the tauriMigrated flag prevents it from running again.

   Fix

   The migration needs to decode the old base64 workspace filename back to a path, then remap it to the new workspaceStorage(pathKey(path)) name before writing. Something like:

   // In migrateFile(), before getStore():
   let storeName = filename === "opencode.settings.dat" ? "opencode.settings" : filename
   
   // Remap old base64-encoded workspace filenames to the new format
   const workspaceMatch = filename.match(/^opencode\.workspace\.([^.]+)\.[^.]+\.dat$/)
   if (workspaceMatch) {
     try {
       const decoded = base64Decode(workspaceMatch[1])  // "Qzpc" → "C:\"
       const key = pathKey(decoded)
       storeName = workspaceStorage(key)
     } catch {
       // not a base64 name, keep original
     }
   }

   This ensures the session data lands in the store the app actually reads.
3. github-actions commented on Jul 14, 2026

   

   github-actionsBot

   on Jul 14, 2026 – with GitHub Actions

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   To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.
4. github-actions

   closed this as not plannedon Jul 14, 2026