tests/test-fastannotate-corrupt.t

revlog: document that mmap resources are released implicitly by GC

It's okay-ish, but currently the open fd and the mapping itself are leaked
until the indexdata is deallocated. If revlog had close(), the underlying
resources should be closed there as well, but AFAIK there's no such hook
point.

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > fastannotate=
  > EOF

  $ hg init repo
  $ cd repo
  $ for i in 0 1 2 3 4; do
  >   echo $i >> a
  >   echo $i >> b
  >   hg commit -A -m $i a b
  > done

use the "debugbuildannotatecache" command to build annotate cache at rev 0

  $ hg debugbuildannotatecache --debug --config fastannotate.mainbranch=0
  fastannotate: a: 1 new changesets in the main branch
  fastannotate: b: 1 new changesets in the main branch

"debugbuildannotatecache" should work with broken cache (and other files would
be built without being affected). note: linelog being broken is only noticed
when we try to append to it.

  $ echo 'CORRUPT!' >> .hg/fastannotate/default/a.m
  $ hg debugbuildannotatecache --debug --config fastannotate.mainbranch=1
  fastannotate: a: rebuilding broken cache
  fastannotate: a: 2 new changesets in the main branch
  fastannotate: b: 1 new changesets in the main branch

  $ echo 'CANNOT REUSE!' > .hg/fastannotate/default/a.l
  $ hg debugbuildannotatecache --debug --config fastannotate.mainbranch=2
  fastannotate: a: rebuilding broken cache
  fastannotate: a: 3 new changesets in the main branch
  fastannotate: b: 1 new changesets in the main branch

  $ rm .hg/fastannotate/default/a.m
  $ hg debugbuildannotatecache --debug --config fastannotate.mainbranch=3
  fastannotate: a: rebuilding broken cache
  fastannotate: a: 4 new changesets in the main branch
  fastannotate: b: 1 new changesets in the main branch

  $ rm .hg/fastannotate/default/a.l
  $ hg debugbuildannotatecache --debug --config fastannotate.mainbranch=3
  $ hg debugbuildannotatecache --debug --config fastannotate.mainbranch=4
  fastannotate: a: rebuilding broken cache
  fastannotate: a: 5 new changesets in the main branch
  fastannotate: b: 1 new changesets in the main branch

"fastannotate" should deal with file corruption as well

  $ rm -rf .hg/fastannotate
  $ hg fastannotate --debug -r 0 a
  fastannotate: a: 1 new changesets in the main branch
  0: 0

  $ echo 'CORRUPT!' >> .hg/fastannotate/default/a.m
  $ hg fastannotate --debug -r 0 a
  fastannotate: a: cache broken and deleted
  fastannotate: a: 1 new changesets in the main branch
  0: 0

  $ echo 'CORRUPT!' > .hg/fastannotate/default/a.l
  $ hg fastannotate --debug -r 1 a
  fastannotate: a: cache broken and deleted
  fastannotate: a: 2 new changesets in the main branch
  0: 0
  1: 1

  $ rm .hg/fastannotate/default/a.l
  $ hg fastannotate --debug -r 1 a
  fastannotate: a: using fast path (resolved fctx: True)
  fastannotate: a: cache broken and deleted
  fastannotate: a: 2 new changesets in the main branch
  0: 0
  1: 1

  $ rm .hg/fastannotate/default/a.m
  $ hg fastannotate --debug -r 2 a
  fastannotate: a: cache broken and deleted
  fastannotate: a: 3 new changesets in the main branch
  0: 0
  1: 1
  2: 2