Fix LnkLst propagation of context_flag when replacing the root during erase

[ironage]

Jonathan reported a failure in a new evergreen runner that was running the client reset tests under a REALM_MAX_BPNODE_SIZE=4 configuration. It turns out that we have never run any sync tests with this enabled on CI. The test happened to hit a case of removing an element from a LnkLst that also had an invalidated object in it and this was causing strange failures.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[2024/03/01 06:23:06.284] 3: realm-object-store-tests is a Catch2 v3.5.2 host application.
[2024/03/01 06:23:06.284] 3: Run with -? for options
[2024/03/01 06:23:06.284] 3:
[2024/03/01 06:23:06.284] 3: -------------------------------------------------------------------------------
[2024/03/01 06:23:06.284] 3: client reset collections of links - cf::ListOfObjects
[2024/03/01 06:23:06.284] 3:   local has unresolved links
[2024/03/01 06:23:06.284] 3:   local adds two new links and remote deletes a different dest object
[2024/03/01 06:23:06.284] 3: -------------------------------------------------------------------------------
[2024/03/01 06:23:06.284] 3: /data/mci/789a545b0869856ff4579cad2dba5e38/realm-core/test/object-store/sync/client_reset.cpp:2987
[2024/03/01 06:23:06.284] 3: ...............................................................................
[2024/03/01 06:23:06.284] 3:
[2024/03/01 06:23:06.284] 3: /data/mci/789a545b0869856ff4579cad2dba5e38/realm-core/test/object-store/sync/client_reset.cpp:2756: FAILED:
[2024/03/01 06:23:06.284] 3:   {Unknown expression after the reported line}
[2024/03/01 06:23:06.284] 3: due to unexpected exception with messages:
[2024/03/01 06:23:06.284] 3:   test_mode := DiscardLocal
[2024/03/01 06:23:06.284] 3:   No object with key '-3' in 'class_dest'
[2024/03/01 06:23:06.284] 3:
[2024/03/01 06:23:06.284] 3: Assertion failure: /data/mci/789a545b0869856ff4579cad2dba5e38/realm-core/test/object-store/sync/client_reset.cpp:2756
[2024/03/01 06:23:06.284] 3: 	 from expresion: '{Unknown expression after the reported line}'
[2024/03/01 06:23:06.284] 3: 	 with expansion: '{Unknown expression after the reported line}'
[2024/03/01 06:23:06.284] 3: 	 message: test_mode := DiscardLocal
[2024/03/01 06:23:06.284] 3: 	 message: No object with key '-3' in 'class_dest'

We were using a ref lookup to get the context flag from an array that had just been deleted, so when doing an erase on a LnkLst that triggered a root_replace, the context flag was always false.

☑️ ToDos

• 📝 Changelog update
• 🚦 Tests (or not relevant)
• C-API, if public C++ API changed
• bindgen/spec.yml, if public C++ API changed

[coveralls-official]

Pull Request Test Coverage Report for Build james.stone_497

Details

• 37 of 38 (97.37%) changed or added relevant lines in 2 files are covered.
• 142 unchanged lines in 14 files lost coverage.
• Overall coverage decreased (-0.01%) to 90.925%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/realm/bplustree.cpp	6	7	85.71%

Files with Coverage Reduction	New Missed Lines	%
src/realm/index_string.hpp	1	93.68%
src/realm/sync/instruction_replication.cpp	1	90.49%
src/realm/list.cpp	2	88.62%
src/realm/sync/noinst/server/server_history.cpp	2	67.94%
src/realm/uuid.cpp	2	97.01%
src/realm/sync/noinst/client_reset.cpp	4	93.07%
src/realm/alloc_slab.cpp	5	92.93%
src/realm/sync/noinst/client_impl_base.cpp	5	85.59%
src/realm/table.cpp	6	90.7%
src/realm/alloc.cpp	8	76.32%

Totals
Change from base Build 2092:	-0.01%
Covered Lines:	238415
Relevant Lines:	262210

---

💛 - Coveralls

[jedelbo]

Good catch!!!

[ironage]

potentially fixes #5405