An edit's preconditions hashed disk contents plus unsaved buffers. Saving a
buffer moved its text from one to the other and changed the hash, so a
quick fix, rename or refactoring listed just before a save (autosave of a
freshly typed scratch, for one) failed with "changed; request the
refactoring again", and only the next attempt worked.
Unsaved buffers now stand in for their files' bytes in the hash, so saving
doesn't change it; edits, external writes and file operations still do.
l0ng-ai
0ecbc6b35d