view tests/test-empty-file.t @ 45545:e5e1285b6f6f

largefiles: prevent in-memory merge instead of switching to on-disk

I enabled in-memory merge by default while testing some changes. I
spent quite some time troubleshooting why largefiles was still
creating an on-disk mergestate. Then I found out that it ignores the
callers `wc` argument to `mergemod._update()` and always uses on-disk
merge. This patch changes that so we raise an error if largefiles is
used with in-memory merge. That way we'll notice if in-memory merge is
used with largefiles instead of silently replacing ignoring the
`overlayworkingctx` instance and updating the working copy instead.

I felt a little bad that this would break things more for users with
both largefiles and in-memory rebase enabled. So I also added a
higher-level override to make sure that largefiles disables in-memory
rebase. It turns out that that fixes `run-tests.py -k largefiles
--extra-config-opt rebase.experimental.inmemory=1`.

Differential Revision: https://phab.mercurial-scm.org/D9069

  $ hg init a
  $ cd a
  $ touch empty1
  $ hg add empty1
  $ hg commit -m 'add empty1'

  $ touch empty2
  $ hg add empty2
  $ hg commit -m 'add empty2'

  $ hg up -C 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ touch empty3
  $ hg add empty3
  $ hg commit -m 'add empty3'
  created new head

  $ hg heads
  changeset:   2:a1cb177e0d44
  tag:         tip
  parent:      0:1e1d9c4e5b64
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add empty3
  
  changeset:   1:097d2b0e17f6
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add empty2
  

  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Before changeset 05257fd28591, we didn't notice the
empty file that came from rev 1:

  $ hg status
  M empty2
  $ hg commit -m merge
  $ hg manifest --debug tip
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty1
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty2
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty3

  $ cd ..