tests/test-largefiles-small-disk.t

largefiles: don't interfere with logging normal files

The previous code was adding standin files to the matcher's file list when
neither the standin file nor the original existed in the context.  Somehow, this
was confusing the logging code into behaving differently from when the extension
wasn't loaded.

It seems that this was an attempt to support naming a directory that only
contains largefiles, as a test fails if the else clause is dropped entirely.
Therefore, only append the "standin" if it is a directory.  This was found by
running the test suite with --config extensions.largefiles=.

The first added test used to log an additional cset that wasn't logged normally.
The only relation it had to file 'a' is that 'a' was the source of a move, but
it isn't clear why having '.hglf/a' in the list causes this change:

    @@ -47,6 +47,11 @@

     Make sure largefiles doesn't interfere with logging a regular file
       $ hg log a --config extensions.largefiles=
    +  changeset:   3:2ca5ba701980
    +  user:        test
    +  date:        Thu Jan 01 00:00:04 1970 +0000
    +  summary:     d
    +
       changeset:   0:9161b9aeaf16
       user:        test
       date:        Thu Jan 01 00:00:01 1970 +0000

The second added test used to complain about a file not being in the parent
revision:

    @@ -1638,10 +1643,8 @@

     Ensure that largefiles doesn't intefere with following a normal file
       $ hg  --config extensions.largefiles= log -f d -T '{desc}' -G
    -  @  c
    -  |
    -  o  a
    -
    +  abort: cannot follow file not in parent revision: ".hglf/d"
    +  [255]
       $ hg log -f d/a -T '{desc}' -G
       @  c
       |

Note that there is still something fishy with the largefiles code, because when
using a glob pattern like this:

    $ hg log 'glob:sub/*'

the pattern list would contain '.hglf/glob:sub/*'.  None of the tests show this
(this test lives in test-largefiles.t at 1349), it was just something that I
noticed when the code was loaded up with print statements.

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