We used to consider deleted files & directories 128 bytes large. After
the delta indexes change a bug slipped in where deleted files would be
weighted according to their old non-deleted size. Both ways are
incorrect (but the latest change made it worse), as if there are more
files deleted than remaining data in the repo the needSize can be
greater than the globalSize, resulting in a negative completion
percentage.
This change makes it so that deleted items are zero bytes large, which
makes more sense. Instead we expose the number of files that we need to
delete as a separate field in the Completion() result, and hack the
percentage down to 95% complete if it was 100% complete but we need to
delete files. This latter part is sort of ugly, but necessary to give
the user some sort of feedback.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3556
5b37d0356c