From 5c8e5560d47e145392905d85b24f1796d6b4daa0 Mon Sep 17 00:00:00 2001
From: Federico Justus Denkena <federico.denkena@posteo.de>
Date: Thu, 10 Sep 2026 00:00:15 +0200
Subject: [PATCH] bisync: default to fail-closed safety flags

New Bisync jobs and scheduled RC bodies start with checkAccess,
deltaList, recover, resilient, slowHashSyncOnly, conflictResolve=none,
maxDelete=50, and checksum compare. Explicit outer values still win.
---
 lib/rclone/constants.ts | 19 +++++++++++++++++++
 lib/rclone/requests.ts  |  6 +++++-
 src/pages/Bisync.tsx    |  7 ++++---
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/lib/rclone/constants.ts b/lib/rclone/constants.ts
index fee26c2..199e404 100644
--- a/lib/rclone/constants.ts
+++ b/lib/rclone/constants.ts
@@ -1,3 +1,22 @@
+// Fail-closed bisync RC defaults (forked rclone). Explicit outer values override.
+export const BISYNC_SAFETY_DEFAULTS = {
+    checkAccess: true,
+    deltaList: true,
+    recover: true,
+    resilient: true,
+    slowHashSyncOnly: true,
+    conflictResolve: 'none',
+    maxDelete: 50,
+    compare: 'size,modtime,checksum',
+} as const
+
+export const BISYNC_SAFETY_SWITCH_DEFAULTS: Record<string, boolean> = {
+    checkAccess: true,
+    deltaList: true,
+    recover: true,
+    resilient: true,
+}
+
 export const RCLONE_CONFIG_DEFAULTS = {
     copy: {
         'multi_thread_cutoff': '64M',
diff --git a/lib/rclone/requests.ts b/lib/rclone/requests.ts
index 0493c47..0490a63 100644
--- a/lib/rclone/requests.ts
+++ b/lib/rclone/requests.ts
@@ -1,4 +1,5 @@
 import type { FlagValue } from '../../types/rclone'
+import { BISYNC_SAFETY_DEFAULTS } from './constants'
 import { getFsInfo } from '../format'
 
 // Pure serialization of operation args into ready-to-POST rclone RC requests. This is the
@@ -492,7 +493,10 @@ export function buildBisyncRequests(args: BisyncArgs): RcRequest[] {
     const { fullDirPath: srcFullDirPath, remoteName: srcRemoteName } = getFsInfo(source)
     const { fullDirPath: dstFullDirPath, remoteName: dstRemoteName } = getFsInfo(destination)
 
-    const outer = { ...(options.outer || {}) }
+    const outer: Record<string, FlagValue> = {
+        ...BISYNC_SAFETY_DEFAULTS,
+        ...(options.outer || {}),
+    }
     // Forked rclone: --delta-list refuses to run without --check-access unless --force.
     if (outer.deltaList && !outer.force) {
         outer.checkAccess = true
diff --git a/src/pages/Bisync.tsx b/src/pages/Bisync.tsx
index bb5ae8f..4166eaf 100644
--- a/src/pages/Bisync.tsx
+++ b/src/pages/Bisync.tsx
@@ -7,7 +7,7 @@ import { onErrorDialog } from '../../lib/errors'
 import { getOptionsSubtitle } from '../../lib/flags'
 import { useFlags } from '../../lib/hooks'
 import { startBisync } from '../../lib/rclone/api'
-import { RCLONE_CONFIG_DEFAULTS } from '../../lib/rclone/constants'
+import { BISYNC_SAFETY_SWITCH_DEFAULTS, RCLONE_CONFIG_DEFAULTS } from '../../lib/rclone/constants'
 import { useSchedulingAvailable } from '../../lib/scheduler'
 import OperationWindowContent from '../components/OperationWindowContent'
 import OperationWindowFooter from '../components/OperationWindowFooter'
@@ -38,7 +38,7 @@ Here's a quick guide to using the Bisync command:
 Use the path selectors at the top to choose Path1 and Path2. Both paths will be kept in sync with each other — there is no "source" or "destination", changes flow both ways.
 
 2. CONFIGURE OPTIONS (Optional)
-Expand the accordion sections to customize your bisync operation. The Bisync section has important switches at the top:
+Expand the accordion sections to customize your bisync operation. Safety defaults are on: checkAccess, deltaList, recover, resilient, conflictResolve=none, maxDelete=50, compare=size,modtime,checksum, slowHashSyncOnly. Turn them off only if you understand the loss path.
 
 • resync — Required for the first run, or to reset bisync after an error. This makes both paths contain a matching superset of all files by copying Path2 to Path1, then Path1 to Path2. Only use resync when starting fresh, after changing filter settings, or recovering from an error — using it routinely would prevent deletions from syncing (deleted files would keep reappearing from the other side).
 
@@ -104,7 +104,8 @@ export default function Bisync() {
     const filterGroup = optionGroups.filter
     const configGroup = optionGroups.config
 
-    const [outerBisyncOptions, setOuterBisyncOptions] = useState<Record<string, boolean>>({})
+    const [outerBisyncOptions, setOuterBisyncOptions] =
+        useState<Record<string, boolean>>(BISYNC_SAFETY_SWITCH_DEFAULTS)
 
     const [cronExpression, setCronExpression] = useState<string | null>(null)
     const schedulingAvailable = useSchedulingAvailable()