What
A new internal flag, keepSessionMessagesCache, starts off (false) and has a setter that can switch it on. While it is on, the step that clears the stored copy of the session's messages, clearSessionMessagesCache, does nothing.
Why
This lets some part of Claude Code keep the stored messages around at times when they would otherwise be thrown away.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say what sets this flag or when.