branching: merge stable into default

Added signature for changeset 787af4e0e8b7

Added tag 6.5.1 for changeset 787af4e0e8b7

relnotes: add 6.5.1

perf: fix perf::tags That return is invalid and unnecessary.

revlog: fix the naming scheme use by split temporary file The `-s` is now added on the first piece only and the `.i` is added to the index. This match the initially intended naming scheme.

revlog: show that temporary split file use broken name scheme The `-s` is added on the wrong part and the `.i` is missing.

fncache: fix a bug that corrupts the fncache after transaction rollback

fncache: add a test demonstrating fncache corruption

transaction: actually delete file created during the transaction on rollback Transaction currently has two modes: - one where file created during the transaction are deleted on rollback, - one where file created during the transaction are truncated to 0 on rollback. Before this change, `hg rollback` and `hg recover` are using the "delete" mode and transaction abort is using the "truncate" option. This difference is never really explained. A long time ago, there was two code paths, with this divergence existing for unclear reasons. When the two code paths got merged into a single one, a boolean argument have been added to preserve this divergence, mostly probably as a cargo cult. The divergence is weird and induce bad surprises, and the truncate behavior is a bit odds, introducing other bad surprises (e.g. 08ecbdba186f) So solve this, we stop using the "truncate" behavior and unify on the "delete" behavior. Despite being currently more "common", the truncate behavior seems less natural, resulting in the transaction leaving empty file around. This is landed on default, early in the cycle, to help us catch problems that could emerge.