intermittent error in terminal while syncing two devices 'Cannot read property 'children' of undefined

[LaurenWags]

Description

Sometimes I see the error below in terminal when two devices are syncing. Once there were missing bookmarks (after waiting a few hours) and the second time there weren't any missing bookmarks.

[18657:18657:1214/180755.351478:ERROR:CONSOLE(0)] "Error in event handler: TypeError: Cannot read property 'children' of undefined
    at Object.NodeState.moveBookmark (chrome://bookmarks/crisper.js:36:3559)
    at Object.NodeState.updateNodes (chrome://bookmarks/crisper.js:36:4755)
    at Object.reduceAction (chrome://bookmarks/crisper.js:36:7120)
    at Store.reduce_ (chrome://bookmarks/crisper.js:44:1112)
    at chrome://bookmarks/crisper.js:44:960
    at Store.dispatchInternal_ (chrome://bookmarks/crisper.js:44:1015)
    at Store.dispatchAsync (chrome://bookmarks/crisper.js:44:869)
    at Store.dispatch (chrome://bookmarks/crisper.js:44:927)
    at dispatch (chrome://bookmarks/crisper.js:48:726)
    at onBookmarkMoved (chrome://bookmarks/crisper.js:48:1287)", source: chrome://bookmarks/?id=9 (0)

Steps to Reproduce

1. Launch devices via terminal (Device A was macOS laptop, Device B was Linux VM)
2. Import bookmarks onto Device A (1-2k)
3. Sync two devices
4. Watch terminal while devices sync.

Actual result:

Sometimes an error is displayed:

[18657:18657:1214/180755.351478:ERROR:CONSOLE(0)] "Error in event handler: TypeError: Cannot read property 'children' of undefined
    at Object.NodeState.moveBookmark (chrome://bookmarks/crisper.js:36:3559)
    at Object.NodeState.updateNodes (chrome://bookmarks/crisper.js:36:4755)
    at Object.reduceAction (chrome://bookmarks/crisper.js:36:7120)
    at Store.reduce_ (chrome://bookmarks/crisper.js:44:1112)
    at chrome://bookmarks/crisper.js:44:960
    at Store.dispatchInternal_ (chrome://bookmarks/crisper.js:44:1015)
    at Store.dispatchAsync (chrome://bookmarks/crisper.js:44:869)
    at Store.dispatch (chrome://bookmarks/crisper.js:44:927)
    at dispatch (chrome://bookmarks/crisper.js:48:726)
    at onBookmarkMoved (chrome://bookmarks/crisper.js:48:1287)", source: chrome://bookmarks/?id=9 (0)

Expected result:

No error

Reproduces how often:

Unsure

Brave version (brave://version info)

Brave	0.58.12 Chromium: 71.0.3578.80 (Official Build) (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Linux

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds? unsure

Website problems only:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Is the issue reproducible on the latest version of Chrome? n/a

Additional Information

cc @brave/legacy_qa

[darkdh]

@AlexeyBarabash this is related to our "Pending Bookmarks"

[AlexeyBarabash]

@darkdh yes, maybe will need to modify chromium js files related to bookmarks.

[btlechowski]

Verification passed on

Brave	0.59.20 Chromium: 72.0.3626.28 (Official Build) beta (64-bit)
Revision	997b1040b63bac324e815797ba52be0cd8f616ed-refs/branch-heads/3626@{#461}
OS	Windows 7

Used test plan from brave/brave-core#1179. No errors in console.
Used STR from OP. No errors in terminal.

Verified passed with

Brave	0.59.20 Chromium: 72.0.3626.28 (Official Build) beta(64-bit)
Revision	997b1040b63bac324e815797ba52be0cd8f616ed-refs/branch-heads/3626@{#461}
OS	Mac OS X

• Verified test plan from Handle invisible nodes (Nodes under Pending Bookmarks and itself) in bookmarks reducer brave-core#1179

Verification passed on Ubuntu 17.10

Brave	0.59.20 Chromium: 72.0.3626.28 (Official Build) beta (64-bit)
Revision	997b1040b63bac324e815797ba52be0cd8f616ed-refs/branch-heads/3626@{#461}
OS	Linux

Used test plan from brave/brave-core#1179. No errors in console.
Used STR from OP. No errors in terminal.