From 1fcd09b89425d607b8747eeaa77eda001fa99841 Mon Sep 17 00:00:00 2001
From: Marcel Klehr <mklehr@gmx.net>
Date: Fri, 8 May 2026 17:49:33 +0200
Subject: [PATCH 1/7] fix(Unidirectional|Merge): Use lower similarity threshold
 for folder similarity

fixes #2230

Signed-off-by: Marcel Klehr <mklehr@gmx.net>
---
 src/lib/Scanner.ts |   2 +-
 src/test/test.js   | 137 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 138 insertions(+), 1 deletion(-)

diff --git a/src/lib/Scanner.ts b/src/lib/Scanner.ts
index ae712e5301..b761db183d 100644
--- a/src/lib/Scanner.ts
+++ b/src/lib/Scanner.ts
@@ -182,7 +182,7 @@ export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation>
             this.mergeable(removedItem, createdItem) &&
             (removedItem.type !== 'folder' ||
               (!this.hasCache &&
-                removedItem.childrenSimilarity(createdItem) > 0.8))
+                removedItem.childrenSimilarity(createdItem) >= 0.5))
           ) {
             this.result.CREATE.retract(createAction)
             this.result.REMOVE.retract(removeAction)
diff --git a/src/test/test.js b/src/test/test.js
index 20230f488d..1d9987ef34 100644
--- a/src/test/test.js
+++ b/src/test/test.js
@@ -2103,6 +2103,143 @@ describe('Floccus', function() {
               false
             )
           })
+          it('should move items without confusing folders (2)', async function() {
+            const localRoot = account.getData().localRoot
+
+            const folder1 = await browser.bookmarks.create({
+              title: 'a',
+              parentId: localRoot
+            })
+            const folder2 = await browser.bookmarks.create({
+              title: 'b',
+              parentId: folder1.id
+            })
+            const folder3 = await browser.bookmarks.create({
+              title: 'c',
+              parentId: folder2.id
+            })
+            const folder4 = await browser.bookmarks.create({
+              title: 'd',
+              parentId: localRoot
+            })
+            const folder5 = await browser.bookmarks.create({
+              title: 'e',
+              parentId: folder4.id,
+            })
+            const folder6 = await browser.bookmarks.create({
+              title: 'f',
+              parentId: folder5.id,
+            })
+            const folderX = await browser.bookmarks.create({
+              title: 'X',
+              parentId: folder3.id,
+            })
+            await browser.bookmarks.create({
+              title: 'url',
+              url: 'http://ur.l/',
+              parentId: folderX.id
+            })
+            const folderX2 = await browser.bookmarks.create({
+              title: 'X',
+              parentId: folder6.id,
+            })
+            await browser.bookmarks.create({
+              title: 'test',
+              url: 'http://urrr.l/',
+              parentId: folderX2.id
+            })
+            const test2Bm = await browser.bookmarks.create({
+              title: 'test2',
+              url: 'http://urrr2.l/',
+              parentId: folder1.id
+            })
+
+            await account.sync() // propagate to server
+            expect(account.getData().error).to.not.be.ok
+
+            await account.sync() // make sure order is propagated
+            expect(account.getData().error).to.not.be.ok
+
+            await account.init() // Remove the cache
+
+            await browser.bookmarks.move(folderX.id, { parentId: folder2.id })
+            await browser.bookmarks.move(folderX2.id, { parentId: folder5.id })
+            await browser.bookmarks.move(test2Bm.id, { parentId: folderX.id })
+
+            await account.sync() // propagate to server
+            expect(account.getData().error).to.not.be.ok
+
+            const tree = await getAllBookmarks(account)
+            expectTreeEqual(
+              tree,
+              new Folder({
+                title: tree.title,
+                children: [
+                  new Folder({
+                    title: 'a',
+                    children: [
+                      new Folder({
+                        title: 'b',
+                        children: [
+                          new Folder({
+                            title: 'c',
+                            children: [],
+                          }),
+                          new Folder({
+                            title: 'X',
+                            children: [
+                              new Bookmark({
+                                title: 'url',
+                                url: 'http://ur.l/',
+                              }),
+                              new Bookmark({
+                                title: 'test2',
+                                url: 'http://urrr2.l/',
+                              }),
+                            ],
+                          }),
+                        ],
+                      }),
+                    ],
+                  }),
+                  new Folder({
+                    title: 'd',
+                    children: [
+                      new Folder({
+                        title: 'e',
+                        children: [
+                          new Folder({
+                            title: 'f',
+                            children: [],
+                          }),
+                          new Folder({
+                            title: 'X',
+                            children: [
+                              new Bookmark({
+                                title: 'test',
+                                url: 'http://urrr.l/',
+                              }),
+                            ],
+                          }),
+                        ],
+                      }),
+                    ],
+                  }),
+                ],
+              }),
+              false,
+              false
+            )
+
+            const localTree = await account.localTree.getBookmarksTree(true)
+            localTree.title = tree.title
+            expectTreeEqual(
+              localTree,
+              tree,
+              false,
+              false
+            )
+          })
           it('should integrate existing items from both sides', async function() {
             const localRoot = account.getData().localRoot
 

From f2b78ad964efae5b51746b14fca60b244565e2c3 Mon Sep 17 00:00:00 2001
From: Marcel Klehr <mklehr@gmx.net>
Date: Fri, 8 May 2026 17:55:30 +0200
Subject: [PATCH 2/7] fix: Run lint:fix

Signed-off-by: Marcel Klehr <mklehr@gmx.net>
---
 src/ui/views/native/Home.vue | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/ui/views/native/Home.vue b/src/ui/views/native/Home.vue
index 668ae360bc..a83362a993 100644
--- a/src/ui/views/native/Home.vue
+++ b/src/ui/views/native/Home.vue
@@ -1,13 +1,14 @@
 <template>
-  <v-alert v-if="!isBrowserSupported" type="error">
+  <v-alert
+    v-if="!isBrowserSupported"
+    type="error">
     {{ 'This browser or WebView is not supported' }}
   </v-alert>
   <v-progress-circular
     v-else
     indeterminate
     color="blue darken-1"
-    class="ma-auto"
-  />
+    class="ma-auto" />
 </template>
 
 <script>

From 6c0df45be556e5fecf41071e11fc1b56dad032cb Mon Sep 17 00:00:00 2001
From: Marcel Klehr <mklehr@gmx.net>
Date: Sat, 9 May 2026 11:07:56 +0200
Subject: [PATCH 3/7] refactor(Scanner): Move mapping creation from mergeable
 fn to diffItem

With this change, mappings will only be created if both childrenSimilarity and mergeable give a go. Before, mergeable would sometimes create mappings prematurely.

Signed-off-by: Marcel Klehr <mklehr@gmx.net>
---
 src/lib/Mappings.ts                  |  2 +
 src/lib/Scanner.ts                   | 50 +++++++++++++++++++++-
 src/lib/strategies/Default.ts        | 63 +++++++++++++++-------------
 src/lib/strategies/Merge.ts          | 47 +++++++--------------
 src/lib/strategies/Unidirectional.ts | 16 ++-----
 5 files changed, 105 insertions(+), 73 deletions(-)

diff --git a/src/lib/Mappings.ts b/src/lib/Mappings.ts
index f87cce1498..ce3b92b0d9 100644
--- a/src/lib/Mappings.ts
+++ b/src/lib/Mappings.ts
@@ -48,6 +48,7 @@ export default class Mappings {
   }
 
   async addFolder({ localId, remoteId }: { localId?:string|number, remoteId?:string|number }):Promise<void> {
+    Mappings.remove(this.folders, { localId, remoteId })
     Mappings.add(this.folders, { localId, remoteId })
   }
 
@@ -56,6 +57,7 @@ export default class Mappings {
   }
 
   async addBookmark({ localId, remoteId }: { localId?:string|number, remoteId?:string|number }):Promise<void> {
+    Mappings.remove(this.bookmarks, { localId, remoteId })
     Mappings.add(this.bookmarks, { localId, remoteId })
   }
 
diff --git a/src/lib/Scanner.ts b/src/lib/Scanner.ts
index b761db183d..c51e91c1ee 100644
--- a/src/lib/Scanner.ts
+++ b/src/lib/Scanner.ts
@@ -4,6 +4,8 @@ import { Bookmark, Folder, ItemLocation, ItemType, TItem, TItemLocation } from '
 import Logger from './Logger'
 import { IHashSettings } from './interfaces/Resource'
 import { yieldToEventLoop } from './yieldToEventLoop'
+import Mappings from './Mappings'
+import optionDownloadLogs from '../ui/components/OptionDownloadLogs.vue'
 
 export interface ScanResult<L1 extends TItemLocation, L2 extends TItemLocation> {
   CREATE: Diff<L1, L2, CreateAction<L1, L2>>
@@ -14,23 +16,36 @@ export interface ScanResult<L1 extends TItemLocation, L2 extends TItemLocation>
 }
 
 export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation> {
+  private mappings: Mappings
   private oldTree: TItem<L1>
   private newTree: TItem<L2>
   private mergeable: (i1: TItem<TItemLocation>, i2: TItem<TItemLocation>) => boolean
   private hashSettings: IHashSettings
   private checkHashes: boolean
   private hasCache: boolean
+  private createMappings: boolean
   private iterations = 0
 
   private result: ScanResult<L2, L1>
 
-  constructor(oldTree:TItem<L1>, newTree:TItem<L2>, mergeable:(i1:TItem<TItemLocation>, i2:TItem<TItemLocation>)=>boolean, hashSettings: IHashSettings, checkHashes = true, hasCache = true) {
+  constructor(
+    mappings: Mappings,
+    oldTree:TItem<L1>,
+    newTree:TItem<L2>,
+    mergeable:(i1:TItem<TItemLocation>, i2:TItem<TItemLocation>)=>boolean,
+    hashSettings: IHashSettings,
+    checkHashes = true,
+    hasCache = true,
+    createMappings = true,
+  ) {
+    this.mappings = mappings
     this.oldTree = oldTree
     this.newTree = newTree
     this.mergeable = mergeable
     this.hashSettings = hashSettings
     this.checkHashes = typeof checkHashes === 'undefined' ? true : checkHashes
     this.hasCache = hasCache
+    this.createMappings = createMappings
     this.result = {
       CREATE: new Diff(),
       UPDATE: new Diff(),
@@ -46,6 +61,7 @@ export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation>
 
   async run():Promise<ScanResult<L2, L1>> {
     await this.diffItem(this.oldTree, this.newTree)
+    Logger.log('Diff before findMoves', this.result)
     await this.findMoves()
     await this.addReorders()
     return this.result
@@ -53,8 +69,14 @@ export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation>
 
   async diffItem(oldItem:TItem<L1>, newItem:TItem<L2>):Promise<void> {
     if (oldItem.type === 'folder' && newItem.type === 'folder') {
+      if (this.createMappings) {
+        await this.addMapping(oldItem, newItem)
+      }
       return this.diffFolder(oldItem, newItem)
     } else if (oldItem.type === 'bookmark' && newItem.type === 'bookmark') {
+      if (this.createMappings) {
+        await this.addMapping(oldItem, newItem)
+      }
       return this.diffBookmark(oldItem, newItem)
     } else {
       throw new Error('Mismatched diff items: ' + oldItem.type + ', ' + newItem.type)
@@ -182,7 +204,7 @@ export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation>
             this.mergeable(removedItem, createdItem) &&
             (removedItem.type !== 'folder' ||
               (!this.hasCache &&
-                removedItem.childrenSimilarity(createdItem) >= 0.5))
+                removedItem.childrenSimilarity(createdItem) >= 0.8))
           ) {
             this.result.CREATE.retract(createAction)
             this.result.REMOVE.retract(removeAction)
@@ -292,6 +314,30 @@ export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation>
     })
   }
 
+  async addMapping(oldItem: TItem<L1>, newItem: TItem<L2>): Promise<void> {
+    let localId, remoteId
+    if (
+      newItem.location === ItemLocation.SERVER &&
+      oldItem.location === ItemLocation.LOCAL
+    ) {
+      localId = oldItem.id
+      remoteId = newItem.id
+    } else if (
+      oldItem.location === ItemLocation.SERVER &&
+      newItem.location === ItemLocation.LOCAL
+    ) {
+      localId = newItem.id
+      remoteId = oldItem.id
+    } else {
+      return
+    }
+    if (newItem.type === 'folder') {
+      await this.mappings.addFolder({ localId, remoteId })
+    } else {
+      await this.mappings.addBookmark({ localId, remoteId })
+    }
+  }
+
   async addReorders(): Promise<void> {
     Logger.log('Scanner: Generate reorders')
     const targets = {}
diff --git a/src/lib/strategies/Default.ts b/src/lib/strategies/Default.ts
index 6c1b9fe050..17ec9553cb 100644
--- a/src/lib/strategies/Default.ts
+++ b/src/lib/strategies/Default.ts
@@ -626,12 +626,11 @@ export default class SyncProcess {
   async getDiffs():Promise<{localScanResult:ScanResult<typeof ItemLocation.LOCAL, TItemLocation>, serverScanResult:ScanResult<typeof ItemLocation.SERVER, TItemLocation>}> {
     const mappingsSnapshot = this.mappings.getSnapshot()
 
-    const newMappings = []
-
     const isUsingTabs = await this.localTree.isUsingBrowserTabs?.()
 
     // Since we have the cache available, Diff cache and both trees..
     const localScanner = new Scanner(
+      this.mappings,
       this.cacheTreeRoot,
       this.localTreeRoot,
       (oldItem, newItem) => {
@@ -656,8 +655,11 @@ export default class SyncProcess {
         return false
       },
       this.hashSettings,
+      true,
+      false,
     )
     const serverScanner = new Scanner(
+      this.mappings,
       this.cacheTreeRoot,
       this.serverTreeRoot,
       (oldItem, newItem) => {
@@ -671,30 +673,28 @@ export default class SyncProcess {
 
         // The two are mappable, no-brainer...
         if (Mappings.mappable(mappingsSnapshot, oldItem, newItem)) {
-          newMappings.push([oldItem, newItem])
           return true
         }
 
         //  We also allow canMergeWith here for bookmarks, because e.g. for NextcloudFolders the id of moved bookmarks changes (because their id is "<bookmarkID>;<folderId>")
         if (oldItem.type === 'bookmark' && newItem.type === 'bookmark' && oldItem.canMergeWith(newItem)) {
-          newMappings.push([oldItem, newItem])
           return true
         }
 
         // We also allow canMergeWith here for folders, if we're dealing with tabs, because Window IDs are not stable
         if (isUsingTabs && oldItem.type === 'folder' && newItem.type === 'folder' && oldItem.canMergeWith(newItem)) {
-          newMappings.push([oldItem, newItem])
           return true
         }
 
         return false
       },
       this.hashSettings,
+      true,
+      true,
     )
     Logger.log('Calculating diffs for local and server trees relative to cache tree')
     const localScanResult = await localScanner.run()
     const serverScanResult = await serverScanner.run()
-    await Parallel.map(newMappings, ([localItem, serverItem]) => this.addMapping(this.server, localItem, serverItem.id), 1)
     return {localScanResult, serverScanResult}
   }
 
@@ -765,26 +765,32 @@ export default class SyncProcess {
       ))
       if (concurrentCreation) {
         // created on both the target and sourcely, try to reconcile
-        const newMappings = []
         const subScanner = new Scanner(
+          this.mappings,
           concurrentCreation.payload, // target tree
           action.payload, // source tree
           (oldItem, newItem) => {
-            if (oldItem.type === newItem.type && oldItem.canMergeWith(newItem)) {
-              // if two items can be merged, we'll add mappings here directly
-              newMappings.push([oldItem, newItem.id])
+            if (
+              oldItem.type === newItem.type &&
+              oldItem.canMergeWith(newItem)
+            ) {
               return true
             }
             return false
           },
           this.hashSettings,
-          false
+          false,
+          true,
+          true,
         )
         const scanResult = await subScanner.run()
-        newMappings.push([concurrentCreation.payload, action.payload.id])
-        await Parallel.each(newMappings, async([oldItem, newId]) => {
-          await this.addMapping(action.payload.location === ItemLocation.LOCAL ? this.localTree : this.server, oldItem, newId)
-        },1)
+        await this.addMapping(
+          action.payload.location === ItemLocation.LOCAL
+            ? this.localTree
+            : this.server,
+          concurrentCreation.payload,
+          action.payload.id
+        )
 
         // SubScanner may reveal residual CREATE/REMOVE actions that we add to the plan here
         // We do not act on REMOVEs, only on CREATEs as we merge the two sides
@@ -1098,25 +1104,25 @@ export default class SyncProcess {
           // Try bulk import with sub folders
           const imported = await resource.bulkImportFolder(id, action.oldItem.copyWithLocation(false, action.payload.location)) as Folder<typeof targetLocation>
           await done()
-          const newMappings = []
           const subScanner = new Scanner(
+            this.mappings,
             action.oldItem,
             imported,
             (oldItem, newItem) => {
-              if (oldItem.type === newItem.type && oldItem.canMergeWith(newItem)) {
-                // if two items can be merged, we'll add mappings here directly
-                newMappings.push([oldItem, newItem.id])
+              if (
+                oldItem.type === newItem.type &&
+                oldItem.canMergeWith(newItem)
+              ) {
                 return true
               }
               return false
             },
             this.hashSettings,
             false,
+            true,
+            true,
           )
           await subScanner.run()
-          await Parallel.each(newMappings, async([oldItem, newId]: [TItem<TItemLocation>, string|number]) => {
-            await this.addMapping(resource, oldItem, newId)
-          }, 10)
 
           if ('orderFolder' in resource) {
             const mappingsSnapshot = this.mappings.getSnapshot()
@@ -1157,25 +1163,26 @@ export default class SyncProcess {
             Logger.log('Attempting chunked bulk import')
             tempItem.children = bookmarks.splice(0, 70)
             const imported = await resource.bulkImportFolder(action.payload.id, tempItem)
-            const newMappings = []
             const subScanner = new Scanner(
+              this.mappings,
               tempItem,
               imported,
               (oldItem, newItem) => {
-                if (oldItem.type === newItem.type && oldItem.canMergeWith(newItem)) {
+                if (
+                  oldItem.type === newItem.type &&
+                  oldItem.canMergeWith(newItem)
+                ) {
                   // if two items can be merged, we'll add mappings here directly
-                  newMappings.push([oldItem, newItem.id])
                   return true
                 }
                 return false
               },
               this.hashSettings,
               false,
+              true,
+              true,
             )
             await subScanner.run()
-            await Parallel.each(newMappings, async([oldItem, newId]: [TItem<TItemLocation>, string|number]) => {
-              await this.addMapping(resource, oldItem, newId)
-            }, 10)
           }
 
           // create sub plan for the folders
diff --git a/src/lib/strategies/Merge.ts b/src/lib/strategies/Merge.ts
index 14f8e5a49a..0f5e6244e5 100644
--- a/src/lib/strategies/Merge.ts
+++ b/src/lib/strategies/Merge.ts
@@ -1,4 +1,4 @@
-import { Folder, ItemLocation, TItem, TItemLocation, TOppositeLocation } from '../Tree'
+import { Folder, ItemLocation, ItemType, TItem, TItemLocation, TOppositeLocation } from '../Tree'
 import Diff, { CreateAction, MoveAction, PlanStage1 } from '../Diff'
 import Scanner, { ScanResult } from '../Scanner'
 import * as Parallel from 'async-parallel'
@@ -15,8 +15,8 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
     serverScanResult: ScanResult<typeof ItemLocation.SERVER, TItemLocation>
   }> {
     // If there's no cache, diff the two trees directly
-    const newMappings: TItem<TItemLocation>[][] = []
     const localScanner = new Scanner(
+      this.mappings,
       this.serverTreeRoot,
       this.localTreeRoot,
       (serverItem, localItem) => {
@@ -24,16 +24,17 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
           localItem.type === serverItem.type &&
           serverItem.canMergeWith(localItem)
         ) {
-          newMappings.push([localItem, serverItem])
           return true
         }
         return false
       },
       this.hashSettings,
       false,
-      false
+      false,
+      true
     )
     const serverScanner = new Scanner(
+      this.mappings,
       this.localTreeRoot,
       this.serverTreeRoot,
       (localItem, serverItem) => {
@@ -41,24 +42,17 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
           serverItem.type === localItem.type &&
           serverItem.canMergeWith(localItem)
         ) {
-          newMappings.push([localItem, serverItem])
           return true
         }
         return false
       },
       this.hashSettings,
       false,
-      false
+      false,
+      true
     )
     const localScanResult = await localScanner.run()
     const serverScanResult = await serverScanner.run()
-    await Parallel.map(
-      newMappings,
-      ([localItem, serverItem]) => {
-        return this.addMapping(this.server, localItem, serverItem.id)
-      },
-      1
-    )
 
     return { localScanResult, serverScanResult }
   }
@@ -119,7 +113,6 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
       REORDER: new Diff(),
     }
 
-    const findChainCacheForCreations = {}
     await Parallel.each(
       sourceScanResult.CREATE.getActions(),
       async(action) => {
@@ -134,8 +127,8 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
         )
         if (concurrentCreation) {
           // created on both the target and sourcely, try to reconcile
-          const newMappings = []
           const subScanner = new Scanner(
+            this.mappings,
             concurrentCreation.payload, // target tree
             action.payload, // source tree
             (oldItem, newItem) => {
@@ -144,7 +137,6 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
                 oldItem.canMergeWith(newItem)
               ) {
                 // if two items can be merged, we'll add mappings here directly
-                newMappings.push([oldItem, newItem.id])
                 return true
               }
               return false
@@ -153,19 +145,12 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
             false
           )
           const scanResult = await subScanner.run()
-          newMappings.push([concurrentCreation.payload, action.payload.id])
-          await Parallel.each(
-            newMappings,
-            async ([oldItem, newId]) => {
-              await this.addMapping(
-                action.payload.location === ItemLocation.LOCAL
-                  ? this.localTree
-                  : this.server,
-                oldItem,
-                newId
-              )
-            },
-            1
+          await this.addMapping(
+            action.payload.location === ItemLocation.LOCAL
+              ? this.localTree
+              : this.server,
+            concurrentCreation.payload,
+            action.payload.id
           )
 
           // SubScanner may reveal residual CREATE/REMOVE actions that we add to the plan here
@@ -320,7 +305,7 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
 
     await Parallel.each(
       sourceScanResult.UPDATE.getActions(),
-      async (action) => {
+      async(action) => {
         const concurrentUpdate = targetUpdates.find(
           (a) =>
             action.payload.type === a.payload.type &&
@@ -338,7 +323,7 @@ export default class MergeSyncProcess extends DefaultSyncProcess {
 
     await Parallel.each(
       sourceScanResult.REORDER.getActions(),
-      async (action) => {
+      async(action) => {
         if (avoidTargetReorders[action.payload.id]) {
           return
         }
diff --git a/src/lib/strategies/Unidirectional.ts b/src/lib/strategies/Unidirectional.ts
index 44c906f631..b504931829 100644
--- a/src/lib/strategies/Unidirectional.ts
+++ b/src/lib/strategies/Unidirectional.ts
@@ -2,7 +2,7 @@ import DefaultStrategy, { ISerializedSyncProcess , ACTION_CONCURRENCY } from './
 import Diff, { Action, ActionType, PlanRevert, PlanStage1, PlanStage3, ReorderAction } from '../Diff'
 import * as Parallel from 'async-parallel'
 import Mappings, { MappingSnapshot } from '../Mappings'
-import { Folder, ItemLocation, TItem, TItemLocation, TOppositeLocation } from '../Tree'
+import { Folder, ItemLocation, ItemType, TItem, TItemLocation, TOppositeLocation } from '../Tree'
 import Logger from '../Logger'
 import { CancelledSyncError } from '../../errors/Error'
 import TResource from '../interfaces/Resource'
@@ -86,7 +86,6 @@ export default class UnidirectionalSyncProcess extends DefaultStrategy {
   async getDiff(): Promise<ScanResult<TItemLocation, TItemLocation>> {
     const mappingsSnapshot = this.mappings.getSnapshot()
 
-    const newMappings = []
     const slaveTree =
       this.direction === ItemLocation.SERVER
         ? this.serverTreeRoot
@@ -96,6 +95,7 @@ export default class UnidirectionalSyncProcess extends DefaultStrategy {
         ? this.localTreeRoot
         : this.serverTreeRoot
     const scanner = new Scanner(
+      this.mappings,
       slaveTree,
       masterTree,
       // We can't rely on a cacheTree, thus we have to accept canMergeWith results as well
@@ -116,30 +116,22 @@ export default class UnidirectionalSyncProcess extends DefaultStrategy {
           return false
         }
         if (serverItem.canMergeWith(localItem)) {
-          newMappings.push([localItem, serverItem])
           return true
         }
         if (Mappings.mappable(mappingsSnapshot, serverItem, localItem)) {
-          newMappings.push([localItem, serverItem])
           return true
         }
         return false
       },
       this.hashSettings,
       false,
-      false
+      false,
+      true
     )
     Logger.log(
       'Unidirectional: Calculating the diff between local and server trees'
     )
     const scanResult = await scanner.run()
-    await Parallel.map(
-      newMappings,
-      ([localItem, serverItem]) => {
-        return this.addMapping(this.server, localItem, serverItem.id)
-      },
-      1
-    )
 
     return scanResult
   }

From c139972e81b54d40296709f474c5b4d2bc0433c3 Mon Sep 17 00:00:00 2001
From: Marcel Klehr <mklehr@gmx.net>
Date: Sat, 9 May 2026 12:01:42 +0200
Subject: [PATCH 4/7] fix: Minor fixes

Signed-off-by: Marcel Klehr <mklehr@gmx.net>
---
 src/lib/Scanner.ts | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/lib/Scanner.ts b/src/lib/Scanner.ts
index c51e91c1ee..93d2f6dd50 100644
--- a/src/lib/Scanner.ts
+++ b/src/lib/Scanner.ts
@@ -5,7 +5,6 @@ import Logger from './Logger'
 import { IHashSettings } from './interfaces/Resource'
 import { yieldToEventLoop } from './yieldToEventLoop'
 import Mappings from './Mappings'
-import optionDownloadLogs from '../ui/components/OptionDownloadLogs.vue'
 
 export interface ScanResult<L1 extends TItemLocation, L2 extends TItemLocation> {
   CREATE: Diff<L1, L2, CreateAction<L1, L2>>
@@ -61,7 +60,6 @@ export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation>
 
   async run():Promise<ScanResult<L2, L1>> {
     await this.diffItem(this.oldTree, this.newTree)
-    Logger.log('Diff before findMoves', this.result)
     await this.findMoves()
     await this.addReorders()
     return this.result

From f5fffd3bf57b2eed306707a428939b172027abab Mon Sep 17 00:00:00 2001
From: Marcel Klehr <mklehr@gmx.net>
Date: Sat, 9 May 2026 17:57:07 +0200
Subject: [PATCH 5/7] tests: Add regression test for confusing moved folders in
 Scanner

Signed-off-by: Marcel Klehr <mklehr@gmx.net>
---
 src/test/test.js | 137 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 137 insertions(+)

diff --git a/src/test/test.js b/src/test/test.js
index 1d9987ef34..add8a252f6 100644
--- a/src/test/test.js
+++ b/src/test/test.js
@@ -4105,6 +4105,143 @@ describe('Floccus', function() {
                 false
               )
             })
+            it('should move items without confusing folders', async function() {
+              const localRoot = account.getData().localRoot
+
+              const folder1 = await browser.bookmarks.create({
+                title: 'a',
+                parentId: localRoot
+              })
+              const folder2 = await browser.bookmarks.create({
+                title: 'b',
+                parentId: folder1.id
+              })
+              const folder3 = await browser.bookmarks.create({
+                title: 'c',
+                parentId: folder2.id
+              })
+              const folder4 = await browser.bookmarks.create({
+                title: 'd',
+                parentId: localRoot
+              })
+              const folder5 = await browser.bookmarks.create({
+                title: 'e',
+                parentId: folder4.id,
+              })
+              const folder6 = await browser.bookmarks.create({
+                title: 'f',
+                parentId: folder5.id,
+              })
+              const folderX = await browser.bookmarks.create({
+                title: 'X',
+                parentId: folder3.id,
+              })
+              await browser.bookmarks.create({
+                title: 'url',
+                url: 'http://ur.l/',
+                parentId: folderX.id
+              })
+              const folderX2 = await browser.bookmarks.create({
+                title: 'X',
+                parentId: folder6.id,
+              })
+              await browser.bookmarks.create({
+                title: 'test',
+                url: 'http://urrr.l/',
+                parentId: folderX2.id
+              })
+              const test2Bm = await browser.bookmarks.create({
+                title: 'test2',
+                url: 'http://urrr2.l/',
+                parentId: folder1.id
+              })
+
+              await account.sync() // propagate to server
+              expect(account.getData().error).to.not.be.ok
+
+              await account.sync() // make sure order is propagated
+              expect(account.getData().error).to.not.be.ok
+
+              await account.init() // remove cache
+
+              await browser.bookmarks.move(folderX.id, { parentId: folder2.id })
+              await browser.bookmarks.move(folderX2.id, { parentId: folder5.id })
+              await browser.bookmarks.move(test2Bm.id, { parentId: folderX.id })
+
+              await account.sync() // propagate to server
+              expect(account.getData().error).to.not.be.ok
+
+              const tree = await getAllBookmarks(account)
+              expectTreeEqual(
+                tree,
+                new Folder({
+                  title: tree.title,
+                  children: [
+                    new Folder({
+                      title: 'a',
+                      children: [
+                        new Folder({
+                          title: 'b',
+                          children: [
+                            new Folder({
+                              title: 'c',
+                              children: [],
+                            }),
+                            new Folder({
+                              title: 'X',
+                              children: [
+                                new Bookmark({
+                                  title: 'url',
+                                  url: 'http://ur.l/',
+                                }),
+                                new Bookmark({
+                                  title: 'test2',
+                                  url: 'http://urrr2.l/',
+                                }),
+                              ],
+                            }),
+                          ],
+                        }),
+                      ],
+                    }),
+                    new Folder({
+                      title: 'd',
+                      children: [
+                        new Folder({
+                          title: 'e',
+                          children: [
+                            new Folder({
+                              title: 'f',
+                              children: [],
+                            }),
+                            new Folder({
+                              title: 'X',
+                              children: [
+                                new Bookmark({
+                                  title: 'test',
+                                  url: 'http://urrr.l/',
+                                }),
+                              ],
+                            }),
+                          ],
+                        }),
+                      ],
+                    }),
+                  ],
+                }),
+                false,
+                false
+              )
+
+              const localTree = await account.localTree.getBookmarksTree(true)
+              localTree.title = tree.title
+              expectTreeEqual(
+                localTree,
+                tree,
+                false,
+                false
+              )
+            })
           })
         })
         context('with two clients', function() {

From 817be1c15579afb76e028ff6dcdb1c46bc3a7e9e Mon Sep 17 00:00:00 2001
From: Marcel Klehr <mklehr@gmx.net>
Date: Sat, 9 May 2026 18:20:35 +0200
Subject: [PATCH 6/7] fix: Throw MappingFailureError on failed id mapping

Signed-off-by: Marcel Klehr <mklehr@gmx.net>
---
 src/lib/Diff.ts             | 17 +++++++++++++++++
 src/lib/strategies/Merge.ts |  2 +-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/lib/Diff.ts b/src/lib/Diff.ts
index 643ec73793..e50df0193c 100644
--- a/src/lib/Diff.ts
+++ b/src/lib/Diff.ts
@@ -335,6 +335,19 @@ export default class Diff<
             action.payload,
             targetLocation
           )
+          if (action.type !== ActionType.CREATE && typeof action.payload.id !== 'undefined' && typeof newAction.payload.id === 'undefined') {
+            Logger.log(
+              'payload.location = ' +
+              action.payload.location +
+              ' | targetLocation = ' +
+              targetLocation
+            )
+            const diff = new Diff()
+            diff.commit(action)
+            Logger.log('Failed to map id of action ' + diff.inspect())
+            Logger.log(JSON.stringify(mappingsSnapshot, null, '\t'))
+            throw new MappingFailureError(String(action.payload.id))
+          }
         }
 
         if (
@@ -397,6 +410,10 @@ export default class Diff<
           })
         }
 
+        if (action.type !== ActionType.REORDER) {
+          Logger.log('Mapped action', action, newAction)
+        }
+
         newDiff.commit(newAction)
       })
     return newDiff
diff --git a/src/lib/strategies/Merge.ts b/src/lib/strategies/Merge.ts
index 0f5e6244e5..688614022c 100644
--- a/src/lib/strategies/Merge.ts
+++ b/src/lib/strategies/Merge.ts
@@ -1,4 +1,4 @@
-import { Folder, ItemLocation, ItemType, TItem, TItemLocation, TOppositeLocation } from '../Tree'
+import { Folder, ItemLocation, TItemLocation, TOppositeLocation } from '../Tree'
 import Diff, { CreateAction, MoveAction, PlanStage1 } from '../Diff'
 import Scanner, { ScanResult } from '../Scanner'
 import * as Parallel from 'async-parallel'

From f0ba511351ce1381ec3698707b8a5a081dec65d5 Mon Sep 17 00:00:00 2001
From: Marcel Klehr <mklehr@gmx.net>
Date: Sat, 9 May 2026 18:38:42 +0200
Subject: [PATCH 7/7] fix(Scanner): Make sure to create mappings for moved
 bookmarks

Signed-off-by: Marcel Klehr <mklehr@gmx.net>
---
 src/lib/Scanner.ts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/lib/Scanner.ts b/src/lib/Scanner.ts
index 93d2f6dd50..017d30097b 100644
--- a/src/lib/Scanner.ts
+++ b/src/lib/Scanner.ts
@@ -263,6 +263,9 @@ export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation>
             reconciled = true
             if (oldItem.type === ItemType.FOLDER) {
               await this.diffItem(oldItem, createdItem)
+            } else if (this.createMappings) {
+              // Usually we let diffItem handle mapping creation but here we need to do it ourselves
+              await this.addMapping(oldItem, createdItem)
             }
           } else {
             const newItem = createdItem.findItemFilter(
@@ -295,6 +298,9 @@ export default class Scanner<L1 extends TItemLocation, L2 extends TItemLocation>
               reconciled = true
               if (removedItem.type === ItemType.FOLDER) {
                 await this.diffItem(removedItem, newItem)
+              } else if (this.createMappings) {
+                // Usually we let diffItem handle mapping creation but here we need to do it ourselves
+                await this.addMapping(removedItem, newItem)
               }
             }
           }