tests/test-lfs-bundle.t

worker: avoid potential partial write of pickled data

Previously, the code wrote the pickled data using os.write(). However,
os.write() can write less bytes than passed to it. To trigger the problem, the
pickled data had to be larger than 2147479552 bytes on my system.

Instead, open a file object and pass it to pickle.dump(). This also has the
advantage that it doesn’t buffer the whole pickled data in memory.

Note that the opened file must be buffered because pickle doesn’t support
unbuffered streams because unbuffered streams’ write() method might write less
bytes than passed to it (like os.write()) but pickle.dump() relies on that all
bytes are written (see https://github.com/python/cpython/issues/93050).

The side effect of using a file object and a with statement is that wfd is
explicitly closed now while it seems like before it was implicitly closed by
process exit.

In this test, we want to test LFS bundle application on both LFS and non-LFS
repos.

To make it more interesting, the file revisions will contain hg filelog
metadata ('\1\n'). The bundle will have 1 file revision overlapping with the
destination repo.

#  rev      1          2         3
#  repo:    yes        yes       no
#  bundle:  no (base)  yes       yes (deltabase: 2 if possible)

It is interesting because rev 2 could have been stored as LFS in the repo, and
non-LFS in the bundle; or vice-versa.

Init

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > lfs=
  > drawdag=$TESTDIR/drawdag.py
  > [lfs]
  > url=file:$TESTTMP/lfs-remote
  > EOF

Helper functions

  $ commitxy() {
  > hg debugdrawdag "$@" <<'EOS'
  >  Y  # Y/X=\1\nAAAA\nE\nF
  >  |  # Y/Y=\1\nAAAA\nG\nH
  >  X  # X/X=\1\nAAAA\nC\n
  >     # X/Y=\1\nAAAA\nD\n
  > EOS
  > }

  $ commitz() {
  > hg debugdrawdag "$@" <<'EOS'
  >  Z  # Z/X=\1\nAAAA\nI\n
  >  |  # Z/Y=\1\nAAAA\nJ\n
  >  |  # Z/Z=\1\nZ
  >  Y
  > EOS
  > }

  $ enablelfs() {
  >   cat >> .hg/hgrc <<EOF
  > [lfs]
  > track=all()
  > EOF
  > }

Generate bundles

  $ for i in normal lfs; do
  >   NAME=src-$i
  >   hg init $TESTTMP/$NAME
  >   cd $TESTTMP/$NAME
  >   [ $i = lfs ] && enablelfs
  >   commitxy
  >   commitz
  >   hg bundle -q --base X -r Y+Z $TESTTMP/$NAME.bundle
  >   SRCNAMES="$SRCNAMES $NAME"
  > done

Prepare destination repos

  $ for i in normal lfs; do
  >   NAME=dst-$i
  >   hg init $TESTTMP/$NAME
  >   cd $TESTTMP/$NAME
  >   [ $i = lfs ] && enablelfs
  >   commitxy
  >   DSTNAMES="$DSTNAMES $NAME"
  > done

Apply bundles

  $ for i in $SRCNAMES; do
  >   for j in $DSTNAMES; do
  >     echo ---- Applying $i.bundle to $j ----
  >     cp -R $TESTTMP/$j $TESTTMP/tmp-$i-$j
  >     cd $TESTTMP/tmp-$i-$j
  >     if hg unbundle $TESTTMP/$i.bundle -q 2>/dev/null; then
  >       hg verify -q && echo OK
  >     else
  >       echo CRASHED
  >     fi
  >   done
  > done
  ---- Applying src-normal.bundle to dst-normal ----
  OK
  ---- Applying src-normal.bundle to dst-lfs ----
  OK
  ---- Applying src-lfs.bundle to dst-normal ----
  OK
  ---- Applying src-lfs.bundle to dst-lfs ----
  OK

Hint if the cache location cannot be inferred from the environment

#if windows
  $ unset LOCALAPPDATA
  $ unset APPDATA
  $ HGRCPATH= hg config lfs --source
  abort: unknown lfs usercache location
  (define LOCALAPPDATA or APPDATA in the environment, or set lfs.usercache)
  [255]
#endif

#if osx
  $ unset HOME
  $ HGRCPATH= hg config lfs --source
  abort: unknown lfs usercache location
  (define HOME in the environment, or set lfs.usercache)
  [255]
#endif

#if no-windows no-osx
  $ unset XDG_CACHE_HOME
  $ unset HOME
  $ HGRCPATH= hg config lfs --source
  abort: unknown lfs usercache location
  (define XDG_CACHE_HOME or HOME in the environment, or set lfs.usercache)
  [255]
#endif