annotate tests/test-largefiles-small-disk.t @ 26750:9f9ec4abe700

cmdutil: make in-memory changes visible to external editor (issue4378)

Before this patch, external editor process for the commit log can't
view some in-memory changes (especially, of dirstate), because they
aren't written out until the end of transaction (or wlock).

This causes unexpected output of Mercurial commands spawned from that
editor process.

To make in-memory changes visible to external editor process, this
patch does:

  - write (or schedule to write) in-memory dirstate changes, and
  - set HG_PENDING environment variable, if:
    - a transaction is running, and
    - there are in-memory changes to be visible

"hg diff" spawned from external editor process for "hg qrefresh"
shows:

  - "changes newly imported into the topmost" before 49148d7868df(*)
  - "all changes recorded in the topmost by refreshing" after this patch

(*) 49148d7868df changed steps invoking editor process

Even though backward compatibility may be broken, the latter behavior
looks reasonable, because "hg diff" spawned from the editor process
consistently shows "what changes new revision records" regardless of
invocation context.

In fact, issue4378 itself should be resolved by 800e090e9c64, which
made 'repo.transaction()' write in-memory dirstate changes out
explicitly before starting transaction. It also made "hg qrefresh"
imply 'dirstate.write()' before external editor invocation in call
chain below.

  - mq.queue.refresh
    - strip.strip
      - repair.strip
        - localrepository.transaction
          - dirstate.write
    - localrepository.commit
      - invoke external editor

Though, this patch has '(issue4378)' in own summary line to indicate
that issues like issue4378 should be fixed by this.

BTW, this patch adds '-m' option to a 'hg ci --amend' execution in
'test-commit-amend.t', to avoid invoking external editor process.

In this case, "unsure" states may be changed to "clean" according to
timestamp or so on. These changes should be written into pending file,
if external editor invocation is required,

Then, writing dirstate changes out breaks stability of test, because
it shows "transaction abort!/rollback completed" occasionally.

Aborting after editor process invocation while commands below may
cause similar instability of tests, too (AFAIK, there is no more such
one, at this revision)

  - commit --amend
    - without --message/--logfile

  - import
    - without --message/--logfile,
    - without --no-commit,
    - without --bypass,
    - one of below, and
      - patch has no description text, or
      - with --edit
    - aborting at the 1st patch, which adds or removes file(s)
      - if it only changes existing files, status is checked only for
        changed files by 'scmutil.matchfiles()', and transition from
        "unsure" to "normal" in dirstate doesn't occur (= dirstate
        isn't changed, and written out)
      - aborting at the 2nd or later patch implies other pending
        changes (e.g. changelog), and always causes showing
        "transaction abort!/rollback completed"

Test how largefiles abort in case the disk runs full

  $ cat > criple.py <<EOF
  > import os, errno, shutil
  > from mercurial import util
  > #
  > # this makes the original largefiles code abort:
  > def copyfileobj(fsrc, fdst, length=16*1024):
  >     fdst.write(fsrc.read(4))
  >     raise IOError(errno.ENOSPC, os.strerror(errno.ENOSPC))
  > shutil.copyfileobj = copyfileobj
  > #
  > # this makes the rewritten code abort:
  > def filechunkiter(f, size=65536, limit=None):
  >     yield f.read(4)
  >     raise IOError(errno.ENOSPC, os.strerror(errno.ENOSPC))
  > util.filechunkiter = filechunkiter
  > #
  > def oslink(src, dest):
  >     raise OSError("no hardlinks, try copying instead")
  > util.oslink = oslink
  > EOF

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "largefiles =" >> $HGRCPATH

  $ hg init alice
  $ cd alice
  $ echo "this is a very big file" > big
  $ hg add --large big
  $ hg commit --config extensions.criple=$TESTTMP/criple.py -m big
  abort: No space left on device
  [255]

The largefile is not created in .hg/largefiles:

  $ ls .hg/largefiles
  dirstate

The user cache is not even created:

  >>> import os; os.path.exists("$HOME/.cache/largefiles/")
  False

Make the commit with space on the device:

  $ hg commit -m big

Now make a clone with a full disk, and make sure lfutil.link function
makes copies instead of hardlinks:

  $ cd ..
  $ hg --config extensions.criple=$TESTTMP/criple.py clone --pull alice bob
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  updating to branch default
  getting changed largefiles
  abort: No space left on device
  [255]

The largefile is not created in .hg/largefiles:

  $ ls bob/.hg/largefiles
  dirstate