Sync crashes browser with "std::__1::basic_string, std::__1::allocator >::assign(char const*, unsigned long)" after re-creation of sync chain

[cezaraugusto]

Description

Re-creating a sync chain causes a browser crash.

Steps to Reproduce

1. Create a sync chain
2. Delete the chain
3. Try re-creating it

Actual result:

Browser crash

Expected result:

It should not crash

Reproduces how often:

Always

Brave version (brave://version info)

Version/Channel Information:

• Can you reproduce this issue with the current release? no
• Can you reproduce this issue with the beta channel? no
• Can you reproduce this issue with the dev channel? no
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

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

Miscellaneous Information:

[kjozwiak]

Crashes with the following signature:

std::__1::basic_string, std::__1::allocator >::assign(char const*, unsigned long)

Added some crash reports that will hopefully narrow down the issue:

Release

• https://stats.brave.com/dashboard#crash/5df1a8d631d93a001fe1a8fc
• https://stats.brave.com/dashboard#crash/5df3ec6658e5df001f57e34d

Nightly

• https://stats.brave.com/dashboard#crash/5df79f3de1515d001f17b6aa
• https://stats.brave.com/dashboard#crash/5df79f7fe1515d001f17b842

Reproduced with the following builds:

Brave	1.4.25 Chromium: 79.0.3945.79 (Official Build) nightly (64-bit)
Revision	29f75ce3f42b007bd80361b0dfcfee3a13ff90b8-refs/branch-heads/3945@{#916}
OS	macOS Version 10.15.1 (Build 19B88)

Brave	1.1.22 Chromium: 79.0.3945.79 (Official Build) (64-bit)
Revision	29f75ce3f42b007bd80361b0dfcfee3a13ff90b8-refs/branch-heads/3945@{#916}
OS	macOS Version 10.15.1 (Build 19B88)

CCing @srirambv @btlechowski

[AlexeyBarabash]

The crash is related to patch https://github.com/brave/brave-core/blob/master/patches/components-sync_device_info-device_info_sync_bridge.cc.patch .

Reverting this patch avoids the crash, but then it is impossible to recreate the chain and the browser hangs on quit.

[LaurenWags]

Verified passed with

Brave	1.3.117 Chromium: 80.0.3987.106 (Official Build) (64-bit)
Revision	f68069574609230cf9b635cd784cfb1bf81bb53a-refs/branch-heads/3987@{#882}
OS	macOS Version 10.14.6 (Build 18G3020)

• After enabling the sync flag, verified the STR from the description
• After enabling the sync flag, verified the test plan from Modify reset sync brave-core#4281
• Confirmed no crashes observed when re-creating sync chains
• Confirmed able to sync as expected (added bookmarks, folders, moved bookmarks, deleted bookmarks, etc) on re-created sync chain when second device was added
• Encountered and logged sometimes get 'Device list is empty' on brave://sync after creating another sync chain - follow up to 7412 #8314 while testing - sometimes an empty sync chain (no devices) is created.

Verification PASSED on Mint 19.1 x64 using the following build:

Brave	1.3.117 Chromium: 80.0.3987.106 (Official Build) (64-bit)
Revision	f68069574609230cf9b635cd784cfb1bf81bb53a-refs/branch-heads/3987@{#882}
OS	Linux

Perquisite: Enabling sync via brave://flags/#brave-sync

• verified the STR outlined under Sync crashes browser with "std::__1::basic_string, std::__1::allocator >::assign(char const*, unsigned long)" after re-creation of sync chain #7412 (comment)
• verified the STR outlined under Modify reset sync brave-core#4281 (comment)
• ensured the browser didn't crash when re-creating sync chain multiple times using the same profile
• Confirmed able to sync as expected (added bookmarks, folders, moved bookmarks, deleted bookmarks, etc) on re-created sync chain when second device was added

Verification passed on

Brave	1.3.118 Chromium: 80.0.3987.116 (Official Build) (64-bit)
Revision	dc00a510e4c2ae25c4d084cc3d946fc782249224-refs/branch-heads/3987@{#917}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

Perquisite: Enabling sync via brave://flags/#brave-sync

• Verified the STR outlined under Sync crashes browser with "std::__1::basic_string, std::__1::allocator >::assign(char const*, unsigned long)" after re-creation of sync chain #7412 (comment)
• verified the STR outlined under Modify reset sync brave-core#4281 (comment)
• ensured the browser didn't crash when re-creating sync chain multiple times using the same profile
• Confirmed able to sync as expected (added bookmarks, folders, moved bookmarks, deleted bookmarks, etc) on re-created sync chain when the second device was added