You'll notice
The diff viewer's 'show more files' toggle is fixed so it can now be collapsed again, not just expanded
What
In the diff/checkpoint viewer, the toggle that expands a collapsed list of changed files to "show more" previously always forced the list open no matter its current state, because the underlying handler always returned true. It now correctly returns the opposite of the current state, so clicking it again collapses the list back.
Why
This fixes a bug where the file list could only ever be expanded, never collapsed back down, once you'd clicked "show more."